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1524 строки
51 KiB
Plaintext
--------------------------------
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bitstring module version history
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--------------------------------
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---------------------------------------
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March 4th 2014: version 3.1.3 released
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---------------------------------------
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This is another bug fix release.
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* Fix for problem with prepend for bitstrings with byte offsets in their data store.
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---------------------------------------
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April 18th 2013: version 3.1.2 released
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---------------------------------------
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This is another bug fix release.
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* Fix for problem where unpacking bytes would by eight times too long
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---------------------------------------
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March 21st 2013: version 3.1.1 released
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---------------------------------------
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This is a bug fix release.
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* Fix for problem where concatenating bitstrings sometimes modified method's arguments
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------------------------------------------
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February 26th 2013: version 3.1.0 released
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------------------------------------------
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This is a minor release with a couple of new features and some bug fixes.
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New 'pad' token
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---------------
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This token can be used in reads and when packing/unpacking to indicate that
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you don't care about the contents of these bits. Any padding bits will just
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be skipped over when reading/unpacking or zero-filled when packing.
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>>> a, b = s.readlist('pad:5, uint:3, pad:1, uint:3')
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Here only two items are returned in the list - the padding bits are ignored.
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New clear and copy convenience methods
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--------------------------------------
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These methods have been introduced in Python 3.3 for lists and bytearrays,
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as more obvious ways of clearing and copying, and we mirror that change here.
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t = s.copy() is equivalent to t = s[:], and s.clear() is equivalent to del s[:].
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Other changes
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-------------
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* Some bug fixes.
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-----------------------------------------
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February 7th 2012: version 3.0.2 released
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-----------------------------------------
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This is a minor update that fixes a few bugs.
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* Fix for subclasses of bitstring classes behaving strangely (Issue 121).
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* Fix for excessive memory usage in rare cases (Issue 120).
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* Fixes for slicing edge cases.
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There has also been a reorganisation of the code to return it to a single
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'bitstring.py' file rather than the package that has been used for the past
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several releases. This change shouldn't affect users directly.
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------------------------------------------
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November 21st 2011: version 3.0.1 released
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------------------------------------------
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This release fixed a small but very visible bug in bitstring printing.
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------------------------------------------
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November 21st 2011: version 3.0.0 released
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------------------------------------------
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This is a major release which breaks backward compatibility in a few places.
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Backwardly incompatible changes
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===============================
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Hex, oct and bin properties don't have leading 0x, 0o and 0b
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------------------------------------------------------------
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If you ask for the hex, octal or binary representations of a bitstring then
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they will no longer be prefixed with '0x', 0o' or '0b'. This was done as it
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was noticed that the first thing a lot of user code does after getting these
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representations was to cut off the first two characters before further
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processing.
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>>> a = BitArray('0x123')
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>>> a.hex, a.oct, a.bin
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('123', '0443', '000100100011')
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Previously this would have returned ('0x123', '0o0443', '0b000100100011')
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This change might require some recoding, but it should all be simplifications.
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ConstBitArray renamed to Bits
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-----------------------------
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Previously Bits was an alias for ConstBitStream (for backward compatibility).
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This has now changed so that Bits and BitArray loosely correspond to the
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built-in types bytes and bytearray.
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If you were using streaming/reading methods on a Bits object then you will
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have to change it to a ConstBitStream.
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The ConstBitArray name is kept as an alias for Bits.
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Stepping in slices has conventional meaning
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-------------------------------------------
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The step parameter in __getitem__, __setitem__ and __delitem__ used to act
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as a multiplier for the start and stop parameters. No one seemed to use it
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though and so it has now reverted to the convential meaning for containers.
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If you are using step then recoding is simple: s[a:b:c] becomes s[a*c:b*c].
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Some examples of the new usage:
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>>> s = BitArray('0x0000')
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s[::4] = [1, 1, 1, 1]
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>>> s.hex
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'8888'
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>>> del s[8::2]
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>>> s.hex
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'880'
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New features
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============
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New readto method
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-----------------
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This method is a mix between a find and a read - it searches for a bitstring
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and then reads up to and including it. For example:
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>>> s = ConstBitStream('0x47000102034704050647')
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>>> s.readto('0x47', bytealigned=True)
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BitStream('0x47')
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>>> s.readto('0x47', bytealigned=True)
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BitStream('0x0001020347')
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>>> s.readto('0x47', bytealigned=True)
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BitStream('0x04050647')
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pack function accepts an iterable as its format
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-----------------------------------------------
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Previously only a string was accepted as the format in the pack function.
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This was an oversight as it broke the symmetry between pack and unpack.
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Now you can use formats like this:
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fmt = ['hex:8', 'bin:3']
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a = pack(fmt, '47', '001')
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a.unpack(fmt)
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--------------------------------------
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June 18th 2011: version 2.2.0 released
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--------------------------------------
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This is a minor upgrade with a couple of new features.
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New interleaved exponential-Golomb interpretations
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--------------------------------------------------
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New bit interpretations for interleaved exponential-Golomb (as used in the
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Dirac video codec) are supplied via 'uie' and 'sie':
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>>> s = BitArray(uie=41)
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>>> s.uie
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41
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>>> s.bin
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'0b00010001001'
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These are pretty similar to the non-interleaved versions - see the manual
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for more details. Credit goes to Paul Sargent for the patch.
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New package-level bytealigned variable
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--------------------------------------
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A number of methods take a 'bytealigned' parameter to indicate that they
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should only work on byte boundaries (e.g. find, replace, split). Previously
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this parameter defaulted to 'False'. Instead it now defaults to
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'bitstring.bytealigned', which itself defaults to 'False', but can be changed
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to modify the default behaviour of the methods. For example:
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>>> a = BitArray('0x00 ff 0f ff')
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>>> a.find('0x0f')
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(4,) # found first not on a byte boundary
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>>> a.find('0x0f', bytealigned=True)
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(16,) # forced looking only on byte boundaries
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>>> bitstring.bytealigned = True # Change default behaviour
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>>> a.find('0x0f')
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(16,)
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>>> a.find('0x0f', bytealigned=False)
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(4,)
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If you're only working with bytes then this can help avoid some errors and
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save some typing!
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Other changes
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-------------
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* Fix for Python 3.2, correcting for a change to the binascii module.
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* Fix for bool initialisation from 0 or 1.
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* Efficiency improvements, including interning strategy.
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------------------------------------------
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February 23rd 2011: version 2.1.1 released
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------------------------------------------
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This is a release to fix a couple of bugs that were introduced in 2.1.0.
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* Bug fix: Reading using the 'bytes' token had been broken (Issue 102).
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* Fixed problem using some methods on ConstBitArrays.
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* Better exception handling for tokens missing values.
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* Some performance improvements.
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-----------------------------------------
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January 23rd 2011: version 2.1.0 released
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-----------------------------------------
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New class hierarchy introduced with simpler classes
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---------------------------------------------------
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Previously there were just two classes, the immutable Bits which was the base
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class for the mutable BitString class. Both of these classes have the concept
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of a bit position, from which reads etc. take place so that the bitstring could
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be treated as if it were a file or stream.
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Two simpler classes have now been added which are purely bit containers and
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don't have a bit position. These are called ConstBitArray and BitArray. As you
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can guess the former is an immutable version of the latter.
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The other classes have also been renamed to better reflect their capabilities.
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Instead of BitString you can use BitStream, and instead of Bits you can use
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ConstBitStream. The old names are kept as aliases for backward compatibility.
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The classes hierarchy is:
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ConstBitArray
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/ \
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/ \
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BitArray ConstBitStream (formerly Bits)
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\ /
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\ /
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BitStream (formerly BitString)
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Other changes
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-------------
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A lot of internal reorganisation has taken place since the previous version,
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most of which won't be noticed by the end user. Some things you might see are:
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* New package structure. Previous versions have been a single file for the
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module and another for the unit tests. The module is now split into many
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more files so it can't be used just by copying bitstring.py any more.
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* To run the unit tests there is now a script called runtests.py in the test
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directory.
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* File based bitstring are now implemented in terms of an mmap. This should
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be just an implementation detail, but unfortunately for 32-bit versions of
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Python this creates a limit of 4GB on the files that can be used. The work
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around is either to get a 64-bit Python, or just stick with version 2.0.
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* The ConstBitArray and ConstBitStream classes no longer copy byte data when
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a slice or a read takes place, they just take a reference. This is mostly
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a very nice optimisation, but there are occassions where it could have an
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adverse effect. For example if a very large bitstring is created, a small
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slice taken and the original deleted. The byte data from the large
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bitstring would still be retained in memory.
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* Optimisations. Once again this version should be faster than the last.
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The module is still pure Python but some of the reorganisation was to make
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it more feasible to put some of the code into Cython or similar, so
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hopefully more speed will be on the way.
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--------------------------------------
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July 26th 2010: version 2.0.3 released
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--------------------------------------
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* Bug fix: Using peek and read for a single bit now returns a new bitstring
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as was intended, rather than the old behaviour of returning a bool.
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* Removed HTML docs from source archive - better to use the online version.
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--------------------------------------
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July 25th 2010: version 2.0.2 released
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--------------------------------------
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This is a major release, with a number of backwardly incompatible changes.
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The main change is the removal of many methods, all of which have simple
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alternatives. Other changes are quite minor but may need some recoding.
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There are a few new features, most of which have been made to help the
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stream-lining of the API. As always there are performance improvements and
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some API changes were made purely with future performance in mind.
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The backwardly incompatible changes are:
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-----------------------------------------
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* Methods removed.
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About half of the class methods have been removed from the API. They all have
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simple alternatives, so what remains is more powerful and easier to remember.
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The removed methods are listed here on the left, with their equivalent
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replacements on the right:
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s.advancebit() -> s.pos += 1
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s.advancebits(bits) -> s.pos += bits
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s.advancebyte() -> s.pos += 8
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s.advancebytes(bytes) -> s.pos += 8*bytes
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s.allunset([a, b]) -> s.all(False, [a, b])
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s.anyunset([a, b]) -> s.any(False, [a, b])
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s.delete(bits, pos) -> del s[pos:pos+bits]
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s.peekbit() -> s.peek(1)
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s.peekbitlist(a, b) -> s.peeklist([a, b])
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s.peekbits(bits) -> s.peek(bits)
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s.peekbyte() -> s.peek(8)
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s.peekbytelist(a, b) -> s.peeklist([8*a, 8*b])
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s.peekbytes(bytes) -> s.peek(8*bytes)
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s.readbit() -> s.read(1)
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s.readbitlist(a, b) -> s.readlist([a, b])
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s.readbits(bits) -> s.read(bits)
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s.readbyte() -> s.read(8)
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s.readbytelist(a, b) -> s.readlist([8*a, 8*b])
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s.readbytes(bytes) -> s.read(8*bytes)
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s.retreatbit() -> s.pos -= 1
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s.retreatbits(bits) -> s.pos -= bits
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s.retreatbyte() -> s.pos -= 8
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s.retreatbytes(bytes) -> s.pos -= 8*bytes
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s.reversebytes(start, end) -> s.byteswap(0, start, end)
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s.seek(pos) -> s.pos = pos
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s.seekbyte(bytepos) -> s.bytepos = bytepos
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s.slice(start, end, step) -> s[start:end:step]
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s.tell() -> s.pos
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s.tellbyte() -> s.bytepos
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s.truncateend(bits) -> del s[-bits:]
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s.truncatestart(bits) -> del s[:bits]
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s.unset([a, b]) -> s.set(False, [a, b])
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Many of these methods have been deprecated for the last few releases, but
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there are some new removals too. Any recoding needed should be quite
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straightforward, so while I apologise for the hassle, I had to take the
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opportunity to streamline and rationalise what was becoming a bit of an
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overblown API.
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* set / unset methods combined.
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The set/unset methods have been combined in a single method, which now
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takes a boolean as its first argument:
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s.set([a, b]) -> s.set(1, [a, b])
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s.unset([a, b]) -> s.set(0, [a, b])
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s.allset([a, b]) -> s.all(1, [a, b])
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s.allunset([a, b]) -> s.all(0, [a, b])
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s.anyset([a, b]) -> s.any(1, [a, b])
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s.anyunset([a, b]) -> s.any(0, [a, b])
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* all / any only accept iterables.
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The all and any methods (previously called allset, allunset, anyset and
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anyunset) no longer accept a single bit position. The recommended way of
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testing a single bit is just to index it, for example instead of:
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>>> if s.all(True, i):
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just use
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>>> if s[i]:
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If you really want to you can of course use an iterable with a single
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element, such as 's.any(False, [i])', but it's clearer just to write
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'not s[i]'.
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* Exception raised on reading off end of bitstring.
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If a read or peek goes beyond the end of the bitstring then a ReadError
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will be raised. The previous behaviour was that the rest of the bitstring
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would be returned and no exception raised.
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* BitStringError renamed to Error.
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The base class for errors in the bitstring module is now just Error, so
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it will likely appears in your code as bitstring.Error instead of
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the rather repetitive bitstring.BitStringError.
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* Single bit slices and reads return a bool.
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A single index slice (such as s[5]) will now return a bool (i.e. True or
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False) rather than a single bit bitstring. This is partly to reflect the
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style of the bytearray type, which returns an integer for single items, but
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mostly to avoid common errors like:
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>>> if s[0]:
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... do_something()
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While the intent of this code snippet is quite clear (i.e. do_something if
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the first bit of s is set) under the old rules s[0] would be true as long
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as s wasn't empty. That's because any one-bit bitstring was true as it was a
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non-empty container. Under the new rule s[0] is True if s starts with a '1'
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bit and False if s starts with a '0' bit.
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The change does not affect reads and peeks, so s.peek(1) will still return
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a single bit bitstring, which leads on to the next item...
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* Empty bitstrings or bitstrings with only zero bits are considered False.
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Previously a bitstring was False if it had no elements, otherwise it was True.
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This is standard behaviour for containers, but wasn't very useful for a container
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of just 0s and 1s. The new behaviour means that the bitstring is False if it
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has no 1 bits. This means that code like this:
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>>> if s.peek(1):
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... do_something()
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should work as you'd expect. It also means that Bits(1000), Bits(0x00) and
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Bits('uint:12=0') are all also False. If you need to check for the emptiness of
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a bitstring then instead check the len property:
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if s -> if s.len
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if not s -> if not s.len
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* Length and offset disallowed for some initialisers.
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Previously you could create bitstring using expressions like:
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>>> s = Bits(hex='0xabcde', offset=4, length=13)
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This has now been disallowed, and the offset and length parameters may only
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be used when initialising with bytes or a file. To replace the old behaviour
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you could instead use
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>>> s = Bits(hex='0xabcde')[4:17]
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* Renamed 'format' parameter 'fmt'.
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Methods with a 'format' parameter have had it renamed to 'fmt', to prevent
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hiding the built-in 'format'. Affects methods unpack, read, peek, readlist,
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peeklist and byteswap and the pack function.
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* Iterables instead of *format accepted for some methods.
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This means that for the affected methods (unpack, readlist and peeklist) you
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will need to use an iterable to specify multiple items. This is easier to
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show than to describe, so instead of
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>>> a, b, c, d = s.readlist('uint:12', 'hex:4', 'bin:7')
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you would instead write
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>>> a, b, c, d = s.readlist(['uint:12', 'hex:4', 'bin:7'])
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Note that you could still use the single string 'uint:12, hex:4, bin:7' if
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you preferred.
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* Bool auto-initialisation removed.
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You can no longer use True and False to initialise single bit bitstrings.
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The reasoning behind this is that as bool is a subclass of int, it really is
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bad practice to have Bits(False) be different to Bits(0) and to have Bits(True)
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different to Bits(1).
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If you have used bool auto-initialisation then you will have to be careful to
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replace it as the bools will now be interpreted as ints, so Bits(False) will
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be empty (a bitstring of length 0), and Bits(True) will be a single zero bit
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(a bitstring of length 1). Sorry for the confusion, but I think this will
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prevent bigger problems in the future.
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There are a few alternatives for creating a single bit bitstring. My favourite
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it to use a list with a single item:
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Bits(False) -> Bits([0])
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Bits(True) -> Bits([1])
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* New creation from file strategy
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Previously if you created a bitstring from a file, either by auto-initialising
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with a file object or using the filename parameter, the file would not be read
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into memory unless you tried to modify it, at which point the whole file would
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be read.
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The new behaviour depends on whether you create a Bits or a BitString from the
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file. If you create a Bits (which is immutable) then the file will never be
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read into memory. This allows very large files to be opened for examination
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even if they could never fit in memory.
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If however you create a BitString, the whole of the referenced file will be read
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to store in memory. If the file is very big this could take a long time, or fail,
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but the idea is that in saying you want the mutable BitString you are implicitly
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saying that you want to make changes and so (for now) we need to load it into
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memory.
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The new strategy is a bit more predictable in terms of performance than the old.
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The main point to remember is that if you want to open a file and don't plan to
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alter the bitstring then use the Bits class rather than BitString.
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Just to be clear, in neither case will the contents of the file ever be changed -
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if you want to output the modified BitString then use the tofile method, for
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example.
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|
|
* find and rfind return a tuple instead of a bool.
|
|
|
|
If a find is unsuccessful then an empty tuple is returned (which is False in a
|
|
boolean sense) otherwise a single item tuple with the bit position is returned
|
|
(which is True in a boolean sense). You shouldn't need to recode unless you
|
|
explicitly compared the result of a find to True or False, for example this
|
|
snippet doesn't need to be altered:
|
|
|
|
>>> if s.find('0x23'):
|
|
... print(s.bitpos)
|
|
|
|
but you could now instead use
|
|
|
|
>>> found = s.find('0x23')
|
|
>>> if found:
|
|
... print(found[0])
|
|
|
|
The reason for returning the bit position in a tuple is so that finding at
|
|
position zero can still be True - it's the tuple (0,) - whereas not found can
|
|
be False - the empty tuple ().
|
|
|
|
The new features in this release are:
|
|
-------------------------------------
|
|
* New count method.
|
|
|
|
This method just counts the number of 1 or 0 bits in the bitstring.
|
|
|
|
>>> s = Bits('0x31fff4')
|
|
>>> s.count(1)
|
|
16
|
|
|
|
* read and peek methods accept integers.
|
|
|
|
The read, readlist, peek and peeklist methods now accept integers as parameters
|
|
to mean "read this many bits and return a bitstring". This has allowed a number
|
|
of methods to be removed from this release, so for example instead of:
|
|
|
|
>>> a, b, c = s.readbits(5, 6, 7)
|
|
>>> if s.peekbit():
|
|
... do_something()
|
|
|
|
you should write:
|
|
|
|
>>> a, b, c = s.readlist([5, 6, 7])
|
|
>>> if s.peek(1):
|
|
... do_something()
|
|
|
|
* byteswap used to reverse all bytes.
|
|
|
|
The byteswap method now allows a format specifier of 0 (the default) to signify
|
|
that all of the whole bytes should be reversed. This means that calling just
|
|
byteswap() is almost equivalent to the now removed bytereverse() method (a small
|
|
difference is that byteswap won't raise an exception if the bitstring isn't a
|
|
whole number of bytes long).
|
|
|
|
* Auto initialise with bytearray or (for Python 3 only) bytes.
|
|
|
|
So rather than writing:
|
|
|
|
>>> a = Bits(bytes=some_bytearray)
|
|
|
|
you can just write
|
|
|
|
>>> a = Bits(some_bytearray)
|
|
|
|
This also works for the bytes type, but only if you're using Python 3.
|
|
For Python 2 it's not possible to distinguish between a bytes object and a
|
|
str. For this reason this method should be used with some caution as it will
|
|
make you code behave differently with the different major Python versions.
|
|
|
|
>>> b = Bits(b'abcd\x23\x00') # Only Python 3!
|
|
|
|
* set, invert, all and any default to whole bitstring.
|
|
|
|
This means that you can for example write:
|
|
|
|
>>> a = BitString(100) # 100 zero bits
|
|
>>> a.set(1) # set all bits to 1
|
|
>>> a.all(1) # are all bits set to 1?
|
|
True
|
|
>>> a.any(0) # are any set to 0?
|
|
False
|
|
>>> a.invert() # invert every bit
|
|
|
|
* New exception types.
|
|
|
|
As well as renaming BitStringError to just Error
|
|
there are also new exceptions which use Error as a base class.
|
|
|
|
These can be caught in preference to Error if you need finer control.
|
|
The new exceptions sometimes also derive from built-in exceptions:
|
|
|
|
ByteAlignError(Error) - whole byte position or length needed.
|
|
|
|
ReadError(Error, IndexError) - reading or peeking off the end of
|
|
the bitstring.
|
|
|
|
CreationError(Error, ValueError) - inappropriate argument during
|
|
bitstring creation.
|
|
|
|
InterpretError(Error, ValueError) - inappropriate interpretation of
|
|
binary data.
|
|
|
|
|
|
--------------------------------------------------------------
|
|
March 18th 2010: version 1.3.0 for Python 2.6 and 3.x released
|
|
--------------------------------------------------------------
|
|
New features:
|
|
|
|
* byteswap method for changing endianness.
|
|
|
|
Changes the endianness in-place according to a format string or
|
|
integer(s) giving the byte pattern. See the manual for details.
|
|
|
|
>>> s = BitString('0x00112233445566')
|
|
>>> s.byteswap(2)
|
|
3
|
|
>>> s
|
|
BitString('0x11003322554466')
|
|
>>> s.byteswap('h')
|
|
3
|
|
>>> s
|
|
BitString('0x00112233445566')
|
|
>>> s.byteswap([2, 5])
|
|
1
|
|
>>> s
|
|
BitString('0x11006655443322')
|
|
|
|
* Multiplicative factors in bitstring creation and reading.
|
|
|
|
For example:
|
|
|
|
>>> s = Bits('100*0x123')
|
|
|
|
* Token grouping using parenthesis.
|
|
|
|
For example:
|
|
|
|
>>> s = Bits('3*(uint:6=3, 0b1)')
|
|
|
|
* Negative slice indices allowed.
|
|
|
|
The start and end parameters of many methods may now be negative, with the
|
|
same meaning as for negative slice indices. Affects all methods with these
|
|
parameters.
|
|
|
|
* Sequence ABCs used.
|
|
|
|
The Bits class now derives from collections.Sequence, while the BitString
|
|
class derives from collections.MutableSequence.
|
|
|
|
* Keywords allowed in readlist, peeklist and unpack.
|
|
|
|
Keywords for token lengths are now permitted when reading. So for example,
|
|
you can write
|
|
|
|
>>> s = bitstring.pack('4*(uint:n)', 2, 3, 4, 5, n=7)
|
|
>>> s.unpack('4*(uint:n)', n=7)
|
|
[2, 3, 4, 5]
|
|
|
|
* start and end parameters added to rol and ror.
|
|
|
|
* join function accepts other iterables.
|
|
|
|
Also its parameter has changed from 'bitstringlist' to 'sequence'. This is
|
|
technically a backward incompatibility in the unlikely event that you are
|
|
referring to the parameter by name.
|
|
|
|
* __init__ method accepts keywords.
|
|
|
|
Rather than a long list of initialisers the __init__ methods now use a
|
|
**kwargs dictionary for all initialisers except 'auto'. This should have no
|
|
effect, except that this is a small backward incompatibility if you use
|
|
positional arguments when initialising with anything other than auto
|
|
(which would be rather unusual).
|
|
|
|
* More optimisations.
|
|
|
|
* Bug fixed in replace method (it could fail if start != 0).
|
|
|
|
----------------------------------------------------------------
|
|
January 19th 2010: version 1.2.0 for Python 2.6 and 3.x released
|
|
----------------------------------------------------------------
|
|
|
|
* New 'Bits' class.
|
|
|
|
Introducing a brand new class, Bits, representing an immutable sequence of
|
|
bits.
|
|
|
|
The Bits class is the base class for the mutable BitString. The differences
|
|
between Bits and BitStrings are:
|
|
|
|
1) Bits are immutable, so once they have been created their value cannot change.
|
|
This of course means that mutating methods (append, replace, del etc.) are not
|
|
available for Bits.
|
|
|
|
2) Bits are hashable, so they can be used in sets and as keys in dictionaries.
|
|
|
|
3) Bits are potentially more efficient than BitStrings, both in terms of
|
|
computation and memory. The current implementation is only marginally
|
|
more efficient though - this should improve in future versions.
|
|
|
|
You can switch from Bits to a BitString or vice versa by constructing a new
|
|
object from the old.
|
|
|
|
>>> s = Bits('0xabcd')
|
|
>>> t = BitString(s)
|
|
>>> t.append('0xe')
|
|
>>> u = Bits(t)
|
|
|
|
The relationship between Bits and BitString is supposed to loosely mirror that
|
|
between bytes and bytearray in Python 3.
|
|
|
|
* Deprecation messages turned on.
|
|
|
|
A number of methods have been flagged for removal in version 2. Deprecation
|
|
warnings will now be given, which include an alternative way to do the same
|
|
thing. All of the deprecated methods have simpler equivalent alternatives.
|
|
|
|
>>> t = s.slice(0, 2)
|
|
__main__:1: DeprecationWarning: Call to deprecated function slice.
|
|
Instead of 's.slice(a, b, c)' use 's[a:b:c]'.
|
|
|
|
The deprecated methods are: advancebit, advancebits, advancebyte, advancebytes,
|
|
retreatbit, retreatbits, retreatbyte, retreatbytes, tell, seek, slice, delete,
|
|
tellbyte, seekbyte, truncatestart and truncateend.
|
|
|
|
* Initialise from bool.
|
|
|
|
Booleans have been added to the list of types that can 'auto'
|
|
initialise a bitstring.
|
|
|
|
>>> zerobit = BitString(False)
|
|
>>> onebit = BitString(True)
|
|
|
|
* Improved efficiency.
|
|
|
|
More methods have been speeded up, in particular some deletions and insertions.
|
|
|
|
* Bug fixes.
|
|
|
|
A rare problem with truncating the start of bitstrings was fixed.
|
|
|
|
A possible problem outputting the final byte in tofile() was fixed.
|
|
|
|
-----------------------------------------------------------------
|
|
December 22nd 2009: version 1.1.3 for Python 2.6 and 3.x released
|
|
-----------------------------------------------------------------
|
|
|
|
This version hopefully fixes an installation problem for platforms with
|
|
case-sensitive file systems. There are no new features or other bug fixes.
|
|
|
|
-----------------------------------------------------------------
|
|
December 18th 2009: version 1.1.2 for Python 2.6 and 3.x released
|
|
-----------------------------------------------------------------
|
|
|
|
This is a minor update with (almost) no new features.
|
|
|
|
* Improved efficiency.
|
|
|
|
The speed of many typical operations has been increased, some substantially.
|
|
|
|
* Initialise from integer.
|
|
|
|
A BitString of '0' bits can be created using just an integer to give the length
|
|
in bits. So instead of
|
|
|
|
>>> s = BitString(length=100)
|
|
|
|
you can write just
|
|
|
|
>>> s = BitString(100)
|
|
|
|
This matches the behaviour of bytearrays and (in Python 3) bytes.
|
|
|
|
* A defect related to using the set / unset functions on BitStrings initialised
|
|
from a file has been fixed.
|
|
|
|
-----------------------------------------------------------------
|
|
November 24th 2009: version 1.1.0 for Python 2.6 and 3.x released
|
|
-----------------------------------------------------------------
|
|
Note that this version will not work for Python 2.4 or 2.5. There may be an
|
|
update for these Python versions some time next year, but it's not a priorty
|
|
quite yet. Also note that only one version is now provided, which works for
|
|
Python 2.6 and 3.x (done with the minimum of hackery!)
|
|
|
|
* Improved efficiency.
|
|
|
|
A fair number of functions have improved efficiency, some quite dramatically.
|
|
|
|
* New bit setting and checking functions.
|
|
|
|
Although these functions don't do anything that couldn't be done before, they
|
|
do make some common use cases much more efficient. If you need to set or check
|
|
single bits then these are the functions you need.
|
|
|
|
set / unset : Set bit(s) to 1 or 0 respectively.
|
|
allset / allunset : Check if all bits are 1 or all 0.
|
|
anyset / anyunset : Check if any bits are 1 or any 0.
|
|
|
|
>>> s = BitString(length=1000)
|
|
>>> s.set((10, 100, 44, 12, 1))
|
|
>>> s.allunset((2, 22, 222))
|
|
True
|
|
>>> s.anyset(range(7, 77))
|
|
True
|
|
|
|
* New rotate functions.
|
|
|
|
ror / rol : Rotate bits to the right or left respectively.
|
|
|
|
>>> s = BitString('0b100000000')
|
|
>>> s.ror(2)
|
|
>>> s.bin
|
|
'0b001000000'
|
|
>>> s.rol(5)
|
|
>>> s.bin
|
|
'0b000000100'
|
|
|
|
* Floating point interpretations.
|
|
|
|
New float initialisations and interpretations are available. These only work
|
|
for BitStrings of length 32 or 64 bits.
|
|
|
|
>>> s = BitString(float=0.2, length=64)
|
|
>>> s.float
|
|
0.200000000000000001
|
|
>>> t = bitstring.pack('<3f', -0.4, 1e34, 17.0)
|
|
>>> t.hex
|
|
'0xcdccccbedf84f67700008841'
|
|
|
|
* 'bytes' token reintroduced.
|
|
|
|
This token returns a bytes object (equivalent to a str in Python 2.6).
|
|
|
|
>>> s = BitString('0x010203')
|
|
>>> s.unpack('bytes:2, bytes:1')
|
|
['\x01\x02', '\x03']
|
|
|
|
* 'uint' is now the default token type.
|
|
|
|
So for example these are equivalent:
|
|
|
|
a, b = s.readlist('uint:12, uint:12')
|
|
a, b = s.readlist('12, 12')
|
|
|
|
--------------------------------------------------------
|
|
October 10th 2009: version 1.0.1 for Python 3.x released
|
|
--------------------------------------------------------
|
|
This is a straight port of version 1.0.0 to Python 3.
|
|
|
|
For changes since the last Python 3 release read all the way down in this
|
|
document to version 0.4.3.
|
|
|
|
This version will also work for Python 2.6, but there's no advantage to using
|
|
it over the 1.0.0 release. It won't work for anything before 2.6.
|
|
|
|
-------------------------------------------------------
|
|
October 9th 2009: version 1.0.0 for Python 2.x released
|
|
-------------------------------------------------------
|
|
Version 1 is here!
|
|
|
|
This is the first release not to carry the 'beta' tag. It contains a couple of
|
|
minor new features but is principally a release to fix the API. If you've been
|
|
using an older version then you almost certainly will have to recode a bit. If
|
|
you're not ready to do that then you may wish to delay updating.
|
|
|
|
So the bad news is that there are lots of small changes to the API. The good
|
|
news is that all the changes are pretty trivial, the new API is cleaner and
|
|
more 'Pythonic', and that by making it version 1.0 I'm promising not to
|
|
tweak it again for some time.
|
|
|
|
** API Changes **
|
|
|
|
* New read / peek functions for returning multiple items.
|
|
|
|
The functions read, readbits, readbytes, peek, peekbits and peekbytes now only
|
|
ever return a single item, never a list.
|
|
|
|
The new functions readlist, readbitlist, readbytelist, peeklist, peekbitlist
|
|
and peekbytelist can be used to read multiple items and will always return a
|
|
list.
|
|
|
|
So a line like:
|
|
|
|
>>> a, b = s.read('uint:12, hex:32')
|
|
|
|
becomes
|
|
|
|
>>> a, b = s.readlist('uint:12, hex:32')
|
|
|
|
* Renaming / removing functions.
|
|
|
|
Functions have been renamed as follows:
|
|
|
|
seekbit -> seek
|
|
tellbit -> tell
|
|
reversebits -> reverse
|
|
deletebits -> delete
|
|
tostring -> tobytes
|
|
|
|
and a couple have been removed altogether:
|
|
|
|
deletebytes - use delete instead.
|
|
empty - use 'not s' rather than 's.empty()'.
|
|
|
|
* Renaming parameters.
|
|
|
|
The parameters 'startbit' and 'endbit' have been renamed 'start' and 'end'.
|
|
This affects the functions slice, find, findall, rfind, reverse, cut and split.
|
|
|
|
The parameter 'bitpos' has been renamed to 'pos'. The affects the functions
|
|
seek, tell, insert, overwrite and delete.
|
|
|
|
* Mutating methods return None rather than self.
|
|
|
|
This means that you can't chain functions together so
|
|
|
|
>>> s.append('0x00').prepend('0xff')
|
|
>>> t = s.reverse()
|
|
|
|
Needs to be rewritten
|
|
|
|
>>> s.append('0x00')
|
|
>>> s.prepend('0xff)
|
|
>>> s.reverse()
|
|
>>> t = s
|
|
|
|
Affects truncatestart, truncateend, insert, overwrite, delete, append,
|
|
prepend, reverse and reversebytes.
|
|
|
|
* Properties renamed.
|
|
|
|
The 'data' property has been renamed to 'bytes'. Also if the BitString is not a
|
|
whole number of bytes then a ValueError exception will be raised when using
|
|
'bytes' as a 'getter'.
|
|
|
|
Properties 'len' and 'pos' have been added to replace 'length' and 'bitpos',
|
|
although the longer names have not been removed so you can continue to use them
|
|
if you prefer.
|
|
|
|
* Other changes.
|
|
|
|
The unpack function now always returns a list, never a single item.
|
|
|
|
BitStrings are now 'unhashable', so calling hash on one or making a set will
|
|
fail.
|
|
|
|
The colon separating the token name from its length is now mandatory. So for
|
|
example BitString('uint12=100') becomes BitString('uint:12=100').
|
|
|
|
Removed support for the 'bytes' token in format strings. Instead of
|
|
s.read('bytes:4') use s.read('bits:32').
|
|
|
|
** New features **
|
|
|
|
* Added endswith and startswith functions.
|
|
|
|
These do much as you'd expect; they return True or False depending on whether
|
|
the BitString starts or ends with the parameter.
|
|
|
|
>>> BitString('0xef342').startswith('0b11101')
|
|
True
|
|
|
|
----------------------------------------------------------
|
|
September 11th 2009: version 0.5.2 for Python 2.x released
|
|
----------------------------------------------------------
|
|
Finally some tools for dealing with endianness!
|
|
|
|
* New interpretations are now available for whole-byte BitStrings that treat
|
|
them as big, little, or native-endian.
|
|
|
|
>>> big = BitString(intbe=1, length=16) # or BitString('intbe:16=1') if you prefer.
|
|
>>> little = BitString(intle=1, length=16)
|
|
>>> print big.hex, little.hex
|
|
0x0001 0x0100
|
|
>>> print big.intbe, little.intle
|
|
1 1
|
|
|
|
* 'Struct'-like compact format codes
|
|
|
|
To save some typing when using pack, unpack, read and peek, compact format
|
|
codes based on those used in the struct and array modules have been added.
|
|
These must start with a character indicating the endianness (>, < or @ for
|
|
big, little and native-endian), followed by characters giving the format:
|
|
|
|
b 1-byte signed int
|
|
B 1-byte unsigned int
|
|
h 2-byte signed int
|
|
H 2-byte unsigned int
|
|
l 4-byte signed int
|
|
L 4-byte unsigned int
|
|
q 8-byte signed int
|
|
Q 8-byte unsigned int
|
|
|
|
For example:
|
|
|
|
>>> s = bitstring.pack('<4h', 0, 1, 2, 3)
|
|
|
|
creates a BitString with four little-endian 2-byte integers. While
|
|
|
|
>>> x, y, z = s.read('>hhl')
|
|
|
|
reads them back as two big-endian two-byte integers and one four-byte big
|
|
endian integer.
|
|
|
|
Of course you can combine this new format with the old ones however you like:
|
|
|
|
>>> s.unpack('<h, intle:24, uint:5, bin')
|
|
[0, 131073, 0, '0b0000000001100000000']
|
|
|
|
-------------------------------------------------------
|
|
August 26th 2009: version 0.5.1 for Python 2.x released
|
|
-------------------------------------------------------
|
|
|
|
This update introduces pack and unpack functions for creating and dissembling
|
|
BitStrings.
|
|
|
|
* New pack() and unpack() functions.
|
|
|
|
The module level pack function provides a flexible new method for creating
|
|
BitStrings. Tokens for BitString 'literals' can be used in the same way as in
|
|
the constructor.
|
|
|
|
>>> from bitstring import BitString, pack
|
|
>>> a = pack('0b11, 0xff, 0o77, int:5=-1, se=33')
|
|
|
|
You can also leave placeholders in the format, which will be filled in by
|
|
the values provided.
|
|
|
|
>>> b = pack('uint:10, hex:4', 33, 'f')
|
|
|
|
Finally you can use a dictionary or keywords.
|
|
|
|
>>> c = pack('bin=a, hex=b, bin=a', a='010', b='ef')
|
|
|
|
The unpack function is similar to the read function except that it always
|
|
unpacks from the start of the BitString.
|
|
|
|
>>> x, y = b.unpack('uint:10, hex')
|
|
|
|
If a token is given without a length (as above) then it will expand to fill the
|
|
remaining bits in the BitString. This also now works with read() and peek().
|
|
|
|
* New tostring() and tofile() functions.
|
|
|
|
The tostring() function just returns the data as a string, with up to seven
|
|
zero bits appended to byte align. The tofile() function does the same except
|
|
writes to a file object.
|
|
|
|
>>> f = open('myfile', 'wb')
|
|
>>> BitString('0x1234ff').tofile(f)
|
|
|
|
* Other changes.
|
|
|
|
The use of '=' is now mandatory in 'auto' initialisers. Tokens like 'uint12 100' will
|
|
no longer work. Also the use of a ':' before the length is encouraged, but not yet
|
|
mandated. So the previous example should be written as 'uint:12=100'.
|
|
|
|
The 'auto' initialiser will now take a file object.
|
|
|
|
>>> f = open('myfile', 'rb')
|
|
>>> s = BitString(f)
|
|
|
|
-----------------------------------------------------
|
|
July 19th 2009: version 0.5.0 for Python 2.x released
|
|
-----------------------------------------------------
|
|
|
|
This update breaks backward compatibility in a couple of areas. The only one
|
|
you probably need to be concerned about is the change to the default for
|
|
bytealigned in find, replace, split, etc.
|
|
|
|
See the user manual for more details on each of these items.
|
|
|
|
* Expanded abilities of 'auto' initialiser.
|
|
|
|
More types can be initialised through the 'auto' initialiser. For example
|
|
instead of
|
|
|
|
>>> a = BitString(uint=44, length=16)
|
|
|
|
you can write
|
|
|
|
>>> a = BitString('uint16=44')
|
|
|
|
Also, different comma-separated tokens will be joined together, e.g.
|
|
|
|
>>> b = BitString('0xff') + 'int8=-5'
|
|
|
|
can be written
|
|
|
|
>>> b = BitString('0xff, int8=-5')
|
|
|
|
* New formatted read() and peek() functions.
|
|
|
|
These takes a format string similar to that used in the auto initialiser.
|
|
If only one token is provided then a single value is returned, otherwise a
|
|
list of values is returned.
|
|
|
|
>>> start_code, width, height = s.read('hex32, uint12, uint12')
|
|
|
|
is equivalent to
|
|
|
|
>>> start_code = s.readbits(32).hex
|
|
>>> width = s.readbits(12).uint
|
|
>>> height = s.readbits(12).uint
|
|
|
|
The tokens are:
|
|
|
|
int n : n bits as an unsigned integer.
|
|
uint n : n bits as a signed integer.
|
|
hex n : n bits as a hexadecimal string.
|
|
oct n : n bits as an octal string.
|
|
bin n : n bits as a binary string.
|
|
ue : next bits as an unsigned exp-Golomb.
|
|
se : next bits as a signed exp-Golomb.
|
|
bits n : n bits as a new BitString.
|
|
bytes n : n bytes as a new BitString.
|
|
|
|
See the user manual for more details.
|
|
|
|
* hex() and oct() functions removed.
|
|
|
|
The special functions for hex() and oct() have been removed. Please use the
|
|
hex and oct properties instead.
|
|
|
|
>>> hex(s)
|
|
|
|
becomes
|
|
|
|
>>> s.hex
|
|
|
|
* join made a member function.
|
|
|
|
The join function must now be called on a BitString object, which will be
|
|
used to join the list together. You may need to recode slightly:
|
|
|
|
>>> s = bitstring.join('0x34', '0b1001', '0b1')
|
|
|
|
becomes
|
|
|
|
>>> s = BitString().join('0x34', '0b1001', '0b1')
|
|
|
|
* More than one value allowed in readbits, readbytes, peekbits and peekbytes
|
|
|
|
If you specify more than one bit or byte length then a list of BitStrings will
|
|
be returned.
|
|
|
|
>>> a, b, c = s.readbits(10, 5, 5)
|
|
|
|
is equivalent to
|
|
|
|
>>> a = readbits(10)
|
|
>>> b = readbits(5)
|
|
>>> c = readbits(5)
|
|
|
|
* bytealigned defaults to False, and is at the end of the parameter list
|
|
|
|
Functions that have a bytealigned paramater have changed so that it now
|
|
defaults to False rather than True. Also its position in the parameter list
|
|
has changed to be at the end. You may need to recode slightly (sorry!)
|
|
|
|
* readue and readse functions have been removed
|
|
|
|
Instead you should use the new read function with a 'ue' or 'se' token:
|
|
|
|
>>> i = s.readue()
|
|
|
|
becomes
|
|
|
|
>>> i = s.read('ue')
|
|
|
|
This is more flexible as you can read multiple items in one go, plus you can
|
|
now also use the peek function with ue and se.
|
|
|
|
* Minor bugs fixed.
|
|
|
|
See the issue tracker for more details.
|
|
|
|
-----------------------------------------------------
|
|
June 15th 2009: version 0.4.3 for Python 2.x released
|
|
-----------------------------------------------------
|
|
|
|
This is a minor update. This release is the first to bundle the bitstring
|
|
manual. This is a PDF and you can find it in the docs directory.
|
|
|
|
Changes in version 0.4.3
|
|
|
|
* New 'cut' function
|
|
|
|
This function returns a generator for constant sized chunks of a BitString.
|
|
|
|
>>> for byte in s.cut(8):
|
|
... do_something_with(byte)
|
|
|
|
You can also specify a startbit and endbit, as well as a count, which limits
|
|
the number of items generated:
|
|
|
|
>>> first100TSPackets = list(s.cut(188*8, count=100))
|
|
|
|
* 'slice' function now equivalent to __getitem__.
|
|
|
|
This means that a step can also be given to the slice function so that the
|
|
following are now the same thing, and it's just a personal preference which
|
|
to use:
|
|
|
|
>>> s1 = s[a:b:c]
|
|
>>> s2 = s.slice(a, b, c)
|
|
|
|
* findall gets a 'count' parameter.
|
|
|
|
So now
|
|
|
|
>>> list(a.findall(s, count=n))
|
|
|
|
is equivalent to
|
|
|
|
>>> list(a.findall(s))[:n]
|
|
|
|
except that it won't need to generate the whole list and so is much more
|
|
efficient.
|
|
|
|
* Changes to 'split'.
|
|
|
|
The split function now has a 'count' parameter rather than 'maxsplit'. This
|
|
makes the interface closer to that for cut, replace and findall. The final item
|
|
generated is now no longer the whole of the rest of the BitString.
|
|
|
|
* A couple of minor bugs were fixed. See the issue tracker for details.
|
|
|
|
----------------------------------------------------
|
|
May 25th 2009: version 0.4.2 for Python 2.x released
|
|
----------------------------------------------------
|
|
|
|
This is a minor update, and almost doesn't break compatibility with version
|
|
0.4.0, but with the slight exception of findall() returning a generator,
|
|
detailed below.
|
|
|
|
Changes in version 0.4.2
|
|
|
|
* Stepping in slices
|
|
|
|
The use of the step parameter (also known as the stride) in slices has been
|
|
added. Its use is a little non-standard as it effectively gives a multiplicative
|
|
factor to apply to the start and stop parameters, rather than skipping over
|
|
bits.
|
|
|
|
For example this makes it much more convenient if you want to give slices in
|
|
terms of bytes instead of bits. Instead of writing s[a*8:b*8] you can use
|
|
s[a:b:8].
|
|
|
|
When using a step the BitString is effectively truncated to a multiple of the
|
|
step, so s[::8] is equal to s if s is an integer number of bytes, otherwise it
|
|
is truncated by up to 7 bits. So the final seven complete 16-bit words could be
|
|
written as s[-7::16]
|
|
|
|
Negative slices are also allowed, and should do what you'd expect. So for
|
|
example s[::-1] returns a bit-reversed copy of s (which is similar to
|
|
s.reversebits(), which does the same operation on s in-place). As another
|
|
example, to get the first 10 bytes in reverse byte order you could use
|
|
s_bytereversed = s[0:10:-8].
|
|
|
|
* Removed restrictions on offset
|
|
|
|
You can now specify an offset of greater than 7 bits when creating a BitString,
|
|
and the use of offset is also now permitted when using the filename initialiser.
|
|
This is useful when you want to create a BitString from the middle of a file
|
|
without having to read the file into memory.
|
|
|
|
>>> f = BitString(filename='reallybigfile', offset=8000000, length=32)
|
|
|
|
* Integers can be assigned to slices
|
|
|
|
You can now assign an integer to a slice of a BitString. If the integer doesn't
|
|
fit in the size of slice given then a ValueError exception is raised. So this
|
|
is now allowed and works as expected:
|
|
|
|
>>> s[8:16] = 106
|
|
|
|
and is equivalent to
|
|
|
|
>>> s[8:16] = BitString(uint=106, length=8)
|
|
|
|
* Less exceptions raised
|
|
|
|
Some changes have been made to slicing so that less exceptions are raised,
|
|
bringing the interface closer to that for lists. So for example trying to delete
|
|
past the end of the BitString will now just delete to the end, rather than
|
|
raising a ValueError.
|
|
|
|
* Initialisation from lists and tuples
|
|
|
|
A new option for the auto initialiser is to pass it a list or tuple. The items
|
|
in the list or tuple are evaluated as booleans and the bits in the BitString are
|
|
set to 1 for True items and 0 for False items. This can be used anywhere the
|
|
auto initialiser can currently be used. For example:
|
|
|
|
>>> a = BitString([True, 7, False, 0, ()]) # 0b11000
|
|
>>> b = a + ['Yes', ''] # Adds '0b10'
|
|
>>> (True, True, False) in a
|
|
True
|
|
|
|
* Miscellany
|
|
|
|
reversebits() now has optional startbit and endbit parameters.
|
|
|
|
As an optimisation findall() will return a generator, rather than a list. If you
|
|
still want the whole list then of course you can just call list() on the
|
|
generator.
|
|
|
|
Improved efficiency of rfind().
|
|
|
|
A couple of minor bugs were fixed. See the issue tracker for details.
|
|
|
|
-----------------------------------------------------
|
|
April 23rd 2009: Python 3 only version 0.4.1 released
|
|
-----------------------------------------------------
|
|
|
|
This version is just a port of version 0.4.0 to Python 3. All the unit tests
|
|
pass, but beyond that only limited ad hoc testing has been done and so it
|
|
should be considered an experimental release. That said, the unit test
|
|
coverage is very good - I'm just not sure if anyone even wants a Python 3
|
|
version!
|
|
|
|
---------------------------------------
|
|
April 11th 2009: version 0.4.0 released
|
|
---------------------------------------
|
|
Changes in version 0.4.0
|
|
|
|
* New functions
|
|
|
|
Added rfind(), findall(), replace(). These do pretty much what you'd expect -
|
|
see the docstrings or the wiki for more information.
|
|
|
|
* More special functions
|
|
|
|
Some missing functions were added: __repr__, __contains__, __rand__,
|
|
__ror__, _rxor__ and __delitem__.
|
|
|
|
* Miscellany
|
|
|
|
A couple of small bugs were fixed (see the issue tracker).
|
|
|
|
----
|
|
|
|
There are some small backward incompatibilities relative to version 0.3.2:
|
|
|
|
* Combined find() and findbytealigned()
|
|
|
|
findbytealigned() has been removed, and becomes part of find(). The default
|
|
start position has changed on both find() and split() to be the start of the
|
|
BitString. You may need to recode:
|
|
|
|
>>> s1.find(bs)
|
|
>>> s2.findbytealigned(bs)
|
|
>>> s2.split(bs)
|
|
|
|
becomes
|
|
|
|
>>> s1.find(bs, bytealigned=False, startbit=s1.bitpos)
|
|
>>> s2.find(bs, startbit=s1.bitpos) # bytealigned defaults to True
|
|
>>> s2.split(bs, startbit=s2.bitpos)
|
|
|
|
* Reading off end of BitString no longer raises exception.
|
|
|
|
Previously a read or peek function that encountered the end of the BitString
|
|
would raise a ValueError. It will now instead return the remainder of the
|
|
BitString, which could be an empty BitString. This is closer to the file
|
|
object interface.
|
|
|
|
* Removed visibility of offset.
|
|
|
|
The offset property was previously read-only, and has now been removed from
|
|
public view altogether. As it is used internally for efficiency reasons you
|
|
shouldn't really have needed to use it. If you do then use the _offset parameter
|
|
instead (with caution).
|
|
|
|
---------------------------------------
|
|
March 11th 2009: version 0.3.2 released
|
|
---------------------------------------
|
|
Changes in version 0.3.2
|
|
|
|
* Better performance
|
|
|
|
A number of functions (especially find() and findbytealigned()) have been sped
|
|
up considerably.
|
|
|
|
* Bit-wise operations
|
|
|
|
Added support for bit-wise AND (&), OR (|) and XOR (^). For example:
|
|
|
|
>>> a = BitString('0b00111')
|
|
>>> print a & '0b10101'
|
|
0b00101
|
|
|
|
* Miscellany
|
|
|
|
Added seekbit() and seekbyte() functions. These complement the 'advance' and
|
|
'retreat' functions, although you can still just use bitpos and bytepos
|
|
properties directly.
|
|
|
|
>>> a.seekbit(100) # Equivalent to a.bitpos = 100
|
|
|
|
Allowed comparisons between BitString objects and strings. For example this
|
|
will now work:
|
|
|
|
>>> a = BitString('0b00001111')
|
|
>>> a == '0x0f'
|
|
True
|
|
|
|
------------------------------------------
|
|
February 26th 2009: version 0.3.1 released
|
|
------------------------------------------
|
|
Changes in version 0.3.1
|
|
|
|
This version only adds features and fixes bugs relative to 0.3.0, and doesn't
|
|
break backwards compatibility.
|
|
|
|
* Octal interpretation and initialisation
|
|
|
|
The oct property now joins bin and hex. Just prefix octal numbers with '0o'.
|
|
|
|
>>> a = BitString('0o755')
|
|
>>> print a.bin
|
|
0b111101101
|
|
|
|
* Simpler copying
|
|
|
|
Rather than using b = copy.copy(a) to create a copy of a BitString, now you
|
|
can just use b = BitString(a).
|
|
|
|
* More special methods
|
|
|
|
Lots of new special methods added, for example bit-shifting via << and >>,
|
|
equality testing via == and !=, bit inversion (~) and concatenation using *.
|
|
|
|
Also __setitem__ is now supported so BitString objects can be modified using
|
|
standard index notation.
|
|
|
|
* Proper installer
|
|
|
|
Finally got round to writing the distutils script. To install just
|
|
python setup.py install.
|
|
|
|
------------------------------------------
|
|
February 15th 2009: version 0.3.0 released
|
|
------------------------------------------
|
|
Changes in version 0.3.0
|
|
|
|
* Simpler initialisation from binary and hexadecimal
|
|
|
|
The first argument in the BitString constructor is now called auto and will
|
|
attempt to interpret the type of a string. Prefix binary numbers with '0b'
|
|
and hexadecimals with '0x'.
|
|
|
|
>>> a = BitString('0b0') # single zero bit
|
|
>>> b = BitString('0xffff') # two bytes
|
|
|
|
Previously the first argument was data, so if you relied on this then you
|
|
will need to recode:
|
|
|
|
>>> a = BitString('\x00\x00\x01\xb3') # Don't do this any more!
|
|
|
|
becomes
|
|
|
|
>>> a = BitString(data='\x00\x00\x01\xb3')
|
|
|
|
or just
|
|
|
|
>>> a = BitString('0x000001b3')
|
|
|
|
This new notation can also be used in functions that take a BitString as an
|
|
argument. For example:
|
|
|
|
>>> a = BitString('0x0011') + '0xff'
|
|
>>> a.insert('0b001', 6)
|
|
>>> a.find('0b1111')
|
|
|
|
* BitString made more mutable
|
|
|
|
The functions append, deletebits, insert, overwrite, truncatestart and
|
|
truncateend now modify the BitString that they act upon. This allows for
|
|
cleaner and more efficient code, but you may need to rewrite slightly if you
|
|
depended upon the old behaviour:
|
|
|
|
>>> a = BitString(hex='0xffff')
|
|
>>> a = a.append(BitString(hex='0x00'))
|
|
>>> b = a.deletebits(10, 10)
|
|
|
|
becomes:
|
|
|
|
>>> a = BitString('0xffff')
|
|
>>> a.append('0x00')
|
|
>>> b = copy.copy(a)
|
|
>>> b.deletebits(10, 10)
|
|
|
|
Thanks to Frank Aune for suggestions in this and other areas.
|
|
|
|
* Changes to printing
|
|
|
|
The binary interpretation of a BitString is now prepended with '0b'. This is
|
|
in keeping with the Python 2.6 (and 3.0) bin function. The prefix is optional
|
|
when initialising using 'bin='.
|
|
|
|
Also, if you just print a BitString with no interpretation it will pick
|
|
something appropriate - hex if it is an integer number of bytes, otherwise
|
|
binary. If the BitString representation is very long it will be truncated
|
|
by '...' so it is only an approximate interpretation.
|
|
|
|
>>> a = BitString('0b0011111')
|
|
>>> print a
|
|
0b0011111
|
|
>>> a += '0b0'
|
|
>>> print a
|
|
0x3e
|
|
|
|
* More convenience functions
|
|
|
|
Some missing functions such as advancebit and deletebytes have been added. Also
|
|
a number of peek functions make an appearance as have prepend and reversebits.
|
|
See the Tutorial for more details.
|
|
|
|
-----------------------------------------
|
|
January 13th 2009: version 0.2.0 released
|
|
-----------------------------------------
|
|
Some fairly minor updates, not really deserving of a whole version point update.
|
|
------------------------------------------
|
|
December 29th 2008: version 0.1.0 released
|
|
------------------------------------------
|
|
First release!
|