gecko-dev/python/voluptuous/voluptuous.py

1955 строки
56 KiB
Python

# encoding: utf-8
#
# Copyright (C) 2010-2013 Alec Thomas <alec@swapoff.org>
# All rights reserved.
#
# This software is licensed as described in the file COPYING, which
# you should have received as part of this distribution.
#
# Author: Alec Thomas <alec@swapoff.org>
"""Schema validation for Python data structures.
Given eg. a nested data structure like this:
{
'exclude': ['Users', 'Uptime'],
'include': [],
'set': {
'snmp_community': 'public',
'snmp_timeout': 15,
'snmp_version': '2c',
},
'targets': {
'localhost': {
'exclude': ['Uptime'],
'features': {
'Uptime': {
'retries': 3,
},
'Users': {
'snmp_community': 'monkey',
'snmp_port': 15,
},
},
'include': ['Users'],
'set': {
'snmp_community': 'monkeys',
},
},
},
}
A schema like this:
>>> settings = {
... 'snmp_community': str,
... 'retries': int,
... 'snmp_version': All(Coerce(str), Any('3', '2c', '1')),
... }
>>> features = ['Ping', 'Uptime', 'Http']
>>> schema = Schema({
... 'exclude': features,
... 'include': features,
... 'set': settings,
... 'targets': {
... 'exclude': features,
... 'include': features,
... 'features': {
... str: settings,
... },
... },
... })
Validate like so:
>>> schema({
... 'set': {
... 'snmp_community': 'public',
... 'snmp_version': '2c',
... },
... 'targets': {
... 'exclude': ['Ping'],
... 'features': {
... 'Uptime': {'retries': 3},
... 'Users': {'snmp_community': 'monkey'},
... },
... },
... }) == {
... 'set': {'snmp_version': '2c', 'snmp_community': 'public'},
... 'targets': {
... 'exclude': ['Ping'],
... 'features': {'Uptime': {'retries': 3},
... 'Users': {'snmp_community': 'monkey'}}}}
True
"""
import collections
import datetime
import inspect
import os
import re
import sys
from contextlib import contextmanager
from functools import wraps
if sys.version_info >= (3,):
import urllib.parse as urlparse
long = int
unicode = str
basestring = str
ifilter = filter
iteritems = lambda d: d.items()
else:
from itertools import ifilter
import urlparse
iteritems = lambda d: d.iteritems()
__author__ = 'Alec Thomas <alec@swapoff.org>'
__version__ = '0.8.11'
@contextmanager
def raises(exc, msg=None, regex=None):
try:
yield
except exc as e:
if msg is not None:
assert str(e) == msg, '%r != %r' % (str(e), msg)
if regex is not None:
assert re.search(regex, str(e)), '%r does not match %r' % (str(e), regex)
class Undefined(object):
def __nonzero__(self):
return False
def __repr__(self):
return '...'
UNDEFINED = Undefined()
def default_factory(value):
if value is UNDEFINED or callable(value):
return value
return lambda: value
# options for extra keys
PREVENT_EXTRA = 0 # any extra key not in schema will raise an error
ALLOW_EXTRA = 1 # extra keys not in schema will be included in output
REMOVE_EXTRA = 2 # extra keys not in schema will be excluded from output
class Error(Exception):
"""Base validation exception."""
class SchemaError(Error):
"""An error was encountered in the schema."""
class Invalid(Error):
"""The data was invalid.
:attr msg: The error message.
:attr path: The path to the error, as a list of keys in the source data.
:attr error_message: The actual error message that was raised, as a
string.
"""
def __init__(self, message, path=None, error_message=None, error_type=None):
Error.__init__(self, message)
self.path = path or []
self.error_message = error_message or message
self.error_type = error_type
@property
def msg(self):
return self.args[0]
def __str__(self):
path = ' @ data[%s]' % ']['.join(map(repr, self.path)) \
if self.path else ''
output = Exception.__str__(self)
if self.error_type:
output += ' for ' + self.error_type
return output + path
def prepend(self, path):
self.path = path + self.path
class MultipleInvalid(Invalid):
def __init__(self, errors=None):
self.errors = errors[:] if errors else []
def __repr__(self):
return 'MultipleInvalid(%r)' % self.errors
@property
def msg(self):
return self.errors[0].msg
@property
def path(self):
return self.errors[0].path
@property
def error_message(self):
return self.errors[0].error_message
def add(self, error):
self.errors.append(error)
def __str__(self):
return str(self.errors[0])
def prepend(self, path):
for error in self.errors:
error.prepend(path)
class RequiredFieldInvalid(Invalid):
"""Required field was missing."""
class ObjectInvalid(Invalid):
"""The value we found was not an object."""
class DictInvalid(Invalid):
"""The value found was not a dict."""
class ExclusiveInvalid(Invalid):
"""More than one value found in exclusion group."""
class InclusiveInvalid(Invalid):
"""Not all values found in inclusion group."""
class SequenceTypeInvalid(Invalid):
"""The type found is not a sequence type."""
class TypeInvalid(Invalid):
"""The value was not of required type."""
class ValueInvalid(Invalid):
"""The value was found invalid by evaluation function."""
class ScalarInvalid(Invalid):
"""Scalars did not match."""
class CoerceInvalid(Invalid):
"""Impossible to coerce value to type."""
class AnyInvalid(Invalid):
"""The value did not pass any validator."""
class AllInvalid(Invalid):
"""The value did not pass all validators."""
class MatchInvalid(Invalid):
"""The value does not match the given regular expression."""
class RangeInvalid(Invalid):
"""The value is not in given range."""
class TrueInvalid(Invalid):
"""The value is not True."""
class FalseInvalid(Invalid):
"""The value is not False."""
class BooleanInvalid(Invalid):
"""The value is not a boolean."""
class UrlInvalid(Invalid):
"""The value is not a url."""
class FileInvalid(Invalid):
"""The value is not a file."""
class DirInvalid(Invalid):
"""The value is not a directory."""
class PathInvalid(Invalid):
"""The value is not a path."""
class LiteralInvalid(Invalid):
"""The literal values do not match."""
class VirtualPathComponent(str):
def __str__(self):
return '<' + self + '>'
def __repr__(self):
return self.__str__()
class Schema(object):
"""A validation schema.
The schema is a Python tree-like structure where nodes are pattern
matched against corresponding trees of values.
Nodes can be values, in which case a direct comparison is used, types,
in which case an isinstance() check is performed, or callables, which will
validate and optionally convert the value.
"""
_extra_to_name = {
REMOVE_EXTRA: 'REMOVE_EXTRA',
ALLOW_EXTRA: 'ALLOW_EXTRA',
PREVENT_EXTRA: 'PREVENT_EXTRA',
}
def __init__(self, schema, required=False, extra=PREVENT_EXTRA):
"""Create a new Schema.
:param schema: Validation schema. See :module:`voluptuous` for details.
:param required: Keys defined in the schema must be in the data.
:param extra: Specify how extra keys in the data are treated:
- :const:`~voluptuous.PREVENT_EXTRA`: to disallow any undefined
extra keys (raise ``Invalid``).
- :const:`~voluptuous.ALLOW_EXTRA`: to include undefined extra
keys in the output.
- :const:`~voluptuous.REMOVE_EXTRA`: to exclude undefined extra keys
from the output.
- Any value other than the above defaults to
:const:`~voluptuous.PREVENT_EXTRA`
"""
self.schema = schema
self.required = required
self.extra = int(extra) # ensure the value is an integer
self._compiled = self._compile(schema)
def __repr__(self):
return "<Schema(%s, extra=%s, required=%s) object at 0x%x>" % (
self.schema, self._extra_to_name.get(self.extra, '??'),
self.required, id(self))
def __call__(self, data):
"""Validate data against this schema."""
try:
return self._compiled([], data)
except MultipleInvalid:
raise
except Invalid as e:
raise MultipleInvalid([e])
# return self.validate([], self.schema, data)
def _compile(self, schema):
if schema is Extra:
return lambda _, v: v
if isinstance(schema, Object):
return self._compile_object(schema)
if isinstance(schema, collections.Mapping):
return self._compile_dict(schema)
elif isinstance(schema, list):
return self._compile_list(schema)
elif isinstance(schema, tuple):
return self._compile_tuple(schema)
type_ = type(schema)
if type_ is type:
type_ = schema
if type_ in (bool, int, long, str, unicode, float, complex, object,
list, dict, type(None)) or callable(schema):
return _compile_scalar(schema)
raise SchemaError('unsupported schema data type %r' %
type(schema).__name__)
def _compile_mapping(self, schema, invalid_msg=None):
"""Create validator for given mapping."""
invalid_msg = invalid_msg or 'mapping value'
# Keys that may be required
all_required_keys = set(key for key in schema
if key is not Extra
and ((self.required and not isinstance(key, (Optional, Remove)))
or isinstance(key, Required)))
# Keys that may have defaults
all_default_keys = set(key for key in schema
if isinstance(key, Required)
or isinstance(key, Optional))
_compiled_schema = {}
for skey, svalue in iteritems(schema):
new_key = self._compile(skey)
new_value = self._compile(svalue)
_compiled_schema[skey] = (new_key, new_value)
candidates = list(_iterate_mapping_candidates(_compiled_schema))
def validate_mapping(path, iterable, out):
required_keys = all_required_keys.copy()
# keeps track of all default keys that haven't been filled
default_keys = all_default_keys.copy()
error = None
errors = []
for key, value in iterable:
key_path = path + [key]
remove_key = False
# compare each given key/value against all compiled key/values
# schema key, (compiled key, compiled value)
for skey, (ckey, cvalue) in candidates:
try:
new_key = ckey(key_path, key)
except Invalid as e:
if len(e.path) > len(key_path):
raise
if not error or len(e.path) > len(error.path):
error = e
continue
# Backtracking is not performed once a key is selected, so if
# the value is invalid we immediately throw an exception.
exception_errors = []
# check if the key is marked for removal
is_remove = new_key is Remove
try:
cval = cvalue(key_path, value)
# include if it's not marked for removal
if not is_remove:
out[new_key] = cval
else:
remove_key = True
continue
except MultipleInvalid as e:
exception_errors.extend(e.errors)
except Invalid as e:
exception_errors.append(e)
if exception_errors:
if is_remove or remove_key:
continue
for err in exception_errors:
if len(err.path) <= len(key_path):
err.error_type = invalid_msg
errors.append(err)
# If there is a validation error for a required
# key, this means that the key was provided.
# Discard the required key so it does not
# create an additional, noisy exception.
required_keys.discard(skey)
break
# Key and value okay, mark any Required() fields as found.
required_keys.discard(skey)
# No need for a default if it was filled
default_keys.discard(skey)
break
else:
if remove_key:
# remove key
continue
elif self.extra == ALLOW_EXTRA:
out[key] = value
elif self.extra != REMOVE_EXTRA:
errors.append(Invalid('extra keys not allowed', key_path))
# else REMOVE_EXTRA: ignore the key so it's removed from output
# set defaults for any that can have defaults
for key in default_keys:
if not isinstance(key.default, Undefined): # if the user provides a default with the node
out[key.schema] = key.default()
if key in required_keys:
required_keys.discard(key)
# for any required keys left that weren't found and don't have defaults:
for key in required_keys:
msg = key.msg if hasattr(key, 'msg') and key.msg else 'required key not provided'
errors.append(RequiredFieldInvalid(msg, path + [key]))
if errors:
raise MultipleInvalid(errors)
return out
return validate_mapping
def _compile_object(self, schema):
"""Validate an object.
Has the same behavior as dictionary validator but work with object
attributes.
For example:
>>> class Structure(object):
... def __init__(self, one=None, three=None):
... self.one = one
... self.three = three
...
>>> validate = Schema(Object({'one': 'two', 'three': 'four'}, cls=Structure))
>>> with raises(MultipleInvalid, "not a valid value for object value @ data['one']"):
... validate(Structure(one='three'))
"""
base_validate = self._compile_mapping(
schema, invalid_msg='object value')
def validate_object(path, data):
if (schema.cls is not UNDEFINED
and not isinstance(data, schema.cls)):
raise ObjectInvalid('expected a {0!r}'.format(schema.cls), path)
iterable = _iterate_object(data)
iterable = ifilter(lambda item: item[1] is not None, iterable)
out = base_validate(path, iterable, {})
return type(data)(**out)
return validate_object
def _compile_dict(self, schema):
"""Validate a dictionary.
A dictionary schema can contain a set of values, or at most one
validator function/type.
A dictionary schema will only validate a dictionary:
>>> validate = Schema({})
>>> with raises(MultipleInvalid, 'expected a dictionary'):
... validate([])
An invalid dictionary value:
>>> validate = Schema({'one': 'two', 'three': 'four'})
>>> with raises(MultipleInvalid, "not a valid value for dictionary value @ data['one']"):
... validate({'one': 'three'})
An invalid key:
>>> with raises(MultipleInvalid, "extra keys not allowed @ data['two']"):
... validate({'two': 'three'})
Validation function, in this case the "int" type:
>>> validate = Schema({'one': 'two', 'three': 'four', int: str})
Valid integer input:
>>> validate({10: 'twenty'})
{10: 'twenty'}
By default, a "type" in the schema (in this case "int") will be used
purely to validate that the corresponding value is of that type. It
will not Coerce the value:
>>> with raises(MultipleInvalid, "extra keys not allowed @ data['10']"):
... validate({'10': 'twenty'})
Wrap them in the Coerce() function to achieve this:
>>> validate = Schema({'one': 'two', 'three': 'four',
... Coerce(int): str})
>>> validate({'10': 'twenty'})
{10: 'twenty'}
Custom message for required key
>>> validate = Schema({Required('one', 'required'): 'two'})
>>> with raises(MultipleInvalid, "required @ data['one']"):
... validate({})
(This is to avoid unexpected surprises.)
Multiple errors for nested field in a dict:
>>> validate = Schema({
... 'adict': {
... 'strfield': str,
... 'intfield': int
... }
... })
>>> try:
... validate({
... 'adict': {
... 'strfield': 123,
... 'intfield': 'one'
... }
... })
... except MultipleInvalid as e:
... print(sorted(str(i) for i in e.errors)) # doctest: +NORMALIZE_WHITESPACE
["expected int for dictionary value @ data['adict']['intfield']",
"expected str for dictionary value @ data['adict']['strfield']"]
"""
base_validate = self._compile_mapping(
schema, invalid_msg='dictionary value')
groups_of_exclusion = {}
groups_of_inclusion = {}
for node in schema:
if isinstance(node, Exclusive):
g = groups_of_exclusion.setdefault(node.group_of_exclusion, [])
g.append(node)
elif isinstance(node, Inclusive):
g = groups_of_inclusion.setdefault(node.group_of_inclusion, [])
g.append(node)
def validate_dict(path, data):
if not isinstance(data, dict):
raise DictInvalid('expected a dictionary', path)
errors = []
for label, group in groups_of_exclusion.items():
exists = False
for exclusive in group:
if exclusive.schema in data:
if exists:
msg = exclusive.msg if hasattr(exclusive, 'msg') and exclusive.msg else \
"two or more values in the same group of exclusion '%s'" % label
next_path = path + [VirtualPathComponent(label)]
errors.append(ExclusiveInvalid(msg, next_path))
break
exists = True
if errors:
raise MultipleInvalid(errors)
for label, group in groups_of_inclusion.items():
included = [node.schema in data for node in group]
if any(included) and not all(included):
msg = "some but not all values in the same group of inclusion '%s'" % label
for g in group:
if hasattr(g, 'msg') and g.msg:
msg = g.msg
break
next_path = path + [VirtualPathComponent(label)]
errors.append(InclusiveInvalid(msg, next_path))
break
if errors:
raise MultipleInvalid(errors)
out = {}
return base_validate(path, iteritems(data), out)
return validate_dict
def _compile_sequence(self, schema, seq_type):
"""Validate a sequence type.
This is a sequence of valid values or validators tried in order.
>>> validator = Schema(['one', 'two', int])
>>> validator(['one'])
['one']
>>> with raises(MultipleInvalid, 'expected int @ data[0]'):
... validator([3.5])
>>> validator([1])
[1]
"""
_compiled = [self._compile(s) for s in schema]
seq_type_name = seq_type.__name__
def validate_sequence(path, data):
if not isinstance(data, seq_type):
raise SequenceTypeInvalid('expected a %s' % seq_type_name, path)
# Empty seq schema, allow any data.
if not schema:
return data
out = []
invalid = None
errors = []
index_path = UNDEFINED
for i, value in enumerate(data):
index_path = path + [i]
invalid = None
for validate in _compiled:
try:
cval = validate(index_path, value)
if cval is not Remove: # do not include Remove values
out.append(cval)
break
except Invalid as e:
if len(e.path) > len(index_path):
raise
invalid = e
else:
errors.append(invalid)
if errors:
raise MultipleInvalid(errors)
return type(data)(out)
return validate_sequence
def _compile_tuple(self, schema):
"""Validate a tuple.
A tuple is a sequence of valid values or validators tried in order.
>>> validator = Schema(('one', 'two', int))
>>> validator(('one',))
('one',)
>>> with raises(MultipleInvalid, 'expected int @ data[0]'):
... validator((3.5,))
>>> validator((1,))
(1,)
"""
return self._compile_sequence(schema, tuple)
def _compile_list(self, schema):
"""Validate a list.
A list is a sequence of valid values or validators tried in order.
>>> validator = Schema(['one', 'two', int])
>>> validator(['one'])
['one']
>>> with raises(MultipleInvalid, 'expected int @ data[0]'):
... validator([3.5])
>>> validator([1])
[1]
"""
return self._compile_sequence(schema, list)
def extend(self, schema, required=None, extra=None):
"""Create a new `Schema` by merging this and the provided `schema`.
Neither this `Schema` nor the provided `schema` are modified. The
resulting `Schema` inherits the `required` and `extra` parameters of
this, unless overridden.
Both schemas must be dictionary-based.
:param schema: dictionary to extend this `Schema` with
:param required: if set, overrides `required` of this `Schema`
:param extra: if set, overrides `extra` of this `Schema`
"""
assert type(self.schema) == dict and type(schema) == dict, 'Both schemas must be dictionary-based'
result = self.schema.copy()
result.update(schema)
result_required = (required if required is not None else self.required)
result_extra = (extra if extra is not None else self.extra)
return Schema(result, required=result_required, extra=result_extra)
def _compile_scalar(schema):
"""A scalar value.
The schema can either be a value or a type.
>>> _compile_scalar(int)([], 1)
1
>>> with raises(Invalid, 'expected float'):
... _compile_scalar(float)([], '1')
Callables have
>>> _compile_scalar(lambda v: float(v))([], '1')
1.0
As a convenience, ValueError's are trapped:
>>> with raises(Invalid, 'not a valid value'):
... _compile_scalar(lambda v: float(v))([], 'a')
"""
if isinstance(schema, type):
def validate_instance(path, data):
if isinstance(data, schema):
return data
else:
msg = 'expected %s' % schema.__name__
raise TypeInvalid(msg, path)
return validate_instance
if callable(schema):
def validate_callable(path, data):
try:
return schema(data)
except ValueError as e:
raise ValueInvalid('not a valid value', path)
except Invalid as e:
e.prepend(path)
raise
return validate_callable
def validate_value(path, data):
if data != schema:
raise ScalarInvalid('not a valid value', path)
return data
return validate_value
def _compile_itemsort():
'''return sort function of mappings'''
def is_extra(key_):
return key_ is Extra
def is_remove(key_):
return isinstance(key_, Remove)
def is_marker(key_):
return isinstance(key_, Marker)
def is_type(key_):
return inspect.isclass(key_)
def is_callable(key_):
return callable(key_)
# priority list for map sorting (in order of checking)
# We want Extra to match last, because it's a catch-all. On the other hand,
# Remove markers should match first (since invalid values will not
# raise an Error, instead the validator will check if other schemas match
# the same value).
priority = [(1, is_remove), # Remove highest priority after values
(2, is_marker), # then other Markers
(4, is_type), # types/classes lowest before Extra
(3, is_callable), # callables after markers
(5, is_extra)] # Extra lowest priority
def item_priority(item_):
key_ = item_[0]
for i, check_ in priority:
if check_(key_):
return i
# values have hightest priorities
return 0
return item_priority
_sort_item = _compile_itemsort()
def _iterate_mapping_candidates(schema):
"""Iterate over schema in a meaningful order."""
# Without this, Extra might appear first in the iterator, and fail to
# validate a key even though it's a Required that has its own validation,
# generating a false positive.
return sorted(iteritems(schema), key=_sort_item)
def _iterate_object(obj):
"""Return iterator over object attributes. Respect objects with
defined __slots__.
"""
d = {}
try:
d = vars(obj)
except TypeError:
# maybe we have named tuple here?
if hasattr(obj, '_asdict'):
d = obj._asdict()
for item in iteritems(d):
yield item
try:
slots = obj.__slots__
except AttributeError:
pass
else:
for key in slots:
if key != '__dict__':
yield (key, getattr(obj, key))
raise StopIteration()
class Object(dict):
"""Indicate that we should work with attributes, not keys."""
def __init__(self, schema, cls=UNDEFINED):
self.cls = cls
super(Object, self).__init__(schema)
class Marker(object):
"""Mark nodes for special treatment."""
def __init__(self, schema, msg=None):
self.schema = schema
self._schema = Schema(schema)
self.msg = msg
def __call__(self, v):
try:
return self._schema(v)
except Invalid as e:
if not self.msg or len(e.path) > 1:
raise
raise Invalid(self.msg)
def __str__(self):
return str(self.schema)
def __repr__(self):
return repr(self.schema)
def __lt__(self, other):
return self.schema < other.schema
class Optional(Marker):
"""Mark a node in the schema as optional, and optionally provide a default
>>> schema = Schema({Optional('key'): str})
>>> schema({})
{}
>>> schema = Schema({Optional('key', default='value'): str})
>>> schema({})
{'key': 'value'}
>>> schema = Schema({Optional('key', default=list): list})
>>> schema({})
{'key': []}
If 'required' flag is set for an entire schema, optional keys aren't required
>>> schema = Schema({
... Optional('key'): str,
... 'key2': str
... }, required=True)
>>> schema({'key2':'value'})
{'key2': 'value'}
"""
def __init__(self, schema, msg=None, default=UNDEFINED):
super(Optional, self).__init__(schema, msg=msg)
self.default = default_factory(default)
class Exclusive(Optional):
"""Mark a node in the schema as exclusive.
Exclusive keys inherited from Optional:
>>> schema = Schema({Exclusive('alpha', 'angles'): int, Exclusive('beta', 'angles'): int})
>>> schema({'alpha': 30})
{'alpha': 30}
Keys inside a same group of exclusion cannot be together, it only makes sense for dictionaries:
>>> with raises(MultipleInvalid, "two or more values in the same group of exclusion 'angles' @ data[<angles>]"):
... schema({'alpha': 30, 'beta': 45})
For example, API can provides multiple types of authentication, but only one works in the same time:
>>> msg = 'Please, use only one type of authentication at the same time.'
>>> schema = Schema({
... Exclusive('classic', 'auth', msg=msg):{
... Required('email'): basestring,
... Required('password'): basestring
... },
... Exclusive('internal', 'auth', msg=msg):{
... Required('secret_key'): basestring
... },
... Exclusive('social', 'auth', msg=msg):{
... Required('social_network'): basestring,
... Required('token'): basestring
... }
... })
>>> with raises(MultipleInvalid, "Please, use only one type of authentication at the same time. @ data[<auth>]"):
... schema({'classic': {'email': 'foo@example.com', 'password': 'bar'},
... 'social': {'social_network': 'barfoo', 'token': 'tEMp'}})
"""
def __init__(self, schema, group_of_exclusion, msg=None):
super(Exclusive, self).__init__(schema, msg=msg)
self.group_of_exclusion = group_of_exclusion
class Inclusive(Optional):
""" Mark a node in the schema as inclusive.
Exclusive keys inherited from Optional:
>>> schema = Schema({
... Inclusive('filename', 'file'): str,
... Inclusive('mimetype', 'file'): str
... })
>>> data = {'filename': 'dog.jpg', 'mimetype': 'image/jpeg'}
>>> data == schema(data)
True
Keys inside a same group of inclusive must exist together, it only makes sense for dictionaries:
>>> with raises(MultipleInvalid, "some but not all values in the same group of inclusion 'file' @ data[<file>]"):
... schema({'filename': 'dog.jpg'})
If none of the keys in the group are present, it is accepted:
>>> schema({})
{}
For example, API can return 'height' and 'width' together, but not separately.
>>> msg = "Height and width must exist together"
>>> schema = Schema({
... Inclusive('height', 'size', msg=msg): int,
... Inclusive('width', 'size', msg=msg): int
... })
>>> with raises(MultipleInvalid, msg + " @ data[<size>]"):
... schema({'height': 100})
>>> with raises(MultipleInvalid, msg + " @ data[<size>]"):
... schema({'width': 100})
>>> data = {'height': 100, 'width': 100}
>>> data == schema(data)
True
"""
def __init__(self, schema, group_of_inclusion, msg=None):
super(Inclusive, self).__init__(schema, msg=msg)
self.group_of_inclusion = group_of_inclusion
class Required(Marker):
"""Mark a node in the schema as being required, and optionally provide a default value.
>>> schema = Schema({Required('key'): str})
>>> with raises(MultipleInvalid, "required key not provided @ data['key']"):
... schema({})
>>> schema = Schema({Required('key', default='value'): str})
>>> schema({})
{'key': 'value'}
>>> schema = Schema({Required('key', default=list): list})
>>> schema({})
{'key': []}
"""
def __init__(self, schema, msg=None, default=UNDEFINED):
super(Required, self).__init__(schema, msg=msg)
self.default = default_factory(default)
class Remove(Marker):
"""Mark a node in the schema to be removed and excluded from the validated
output. Keys that fail validation will not raise ``Invalid``. Instead, these
keys will be treated as extras.
>>> schema = Schema({str: int, Remove(int): str})
>>> with raises(MultipleInvalid, "extra keys not allowed @ data[1]"):
... schema({'keep': 1, 1: 1.0})
>>> schema({1: 'red', 'red': 1, 2: 'green'})
{'red': 1}
>>> schema = Schema([int, Remove(float), Extra])
>>> schema([1, 2, 3, 4.0, 5, 6.0, '7'])
[1, 2, 3, 5, '7']
"""
def __call__(self, v):
super(Remove, self).__call__(v)
return self.__class__
def __repr__(self):
return "Remove(%r)" % (self.schema,)
def Extra(_):
"""Allow keys in the data that are not present in the schema."""
raise SchemaError('"Extra" should never be called')
# As extra() is never called there's no way to catch references to the
# deprecated object, so we just leave an alias here instead.
extra = Extra
class Msg(object):
"""Report a user-friendly message if a schema fails to validate.
>>> validate = Schema(
... Msg(['one', 'two', int],
... 'should be one of "one", "two" or an integer'))
>>> with raises(MultipleInvalid, 'should be one of "one", "two" or an integer'):
... validate(['three'])
Messages are only applied to invalid direct descendants of the schema:
>>> validate = Schema(Msg([['one', 'two', int]], 'not okay!'))
>>> with raises(MultipleInvalid, 'expected int @ data[0][0]'):
... validate([['three']])
The type which is thrown can be overridden but needs to be a subclass of Invalid
>>> with raises(SchemaError, 'Msg can only use subclases of Invalid as custom class'):
... validate = Schema(Msg([int], 'should be int', cls=KeyError))
If you do use a subclass of Invalid, that error will be thrown (wrapped in a MultipleInvalid)
>>> validate = Schema(Msg([['one', 'two', int]], 'not okay!', cls=RangeInvalid))
>>> try:
... validate(['three'])
... except MultipleInvalid as e:
... assert isinstance(e.errors[0], RangeInvalid)
"""
def __init__(self, schema, msg, cls=None):
if cls and not issubclass(cls, Invalid):
raise SchemaError("Msg can only use subclases of"
" Invalid as custom class")
self._schema = schema
self.schema = Schema(schema)
self.msg = msg
self.cls = cls
def __call__(self, v):
try:
return self.schema(v)
except Invalid as e:
if len(e.path) > 1:
raise e
else:
raise (self.cls or Invalid)(self.msg)
def __repr__(self):
return 'Msg(%s, %s, cls=%s)' % (self._schema, self.msg, self.cls)
def message(default=None, cls=None):
"""Convenience decorator to allow functions to provide a message.
Set a default message:
>>> @message('not an integer')
... def isint(v):
... return int(v)
>>> validate = Schema(isint())
>>> with raises(MultipleInvalid, 'not an integer'):
... validate('a')
The message can be overridden on a per validator basis:
>>> validate = Schema(isint('bad'))
>>> with raises(MultipleInvalid, 'bad'):
... validate('a')
The class thrown too:
>>> class IntegerInvalid(Invalid): pass
>>> validate = Schema(isint('bad', clsoverride=IntegerInvalid))
>>> try:
... validate('a')
... except MultipleInvalid as e:
... assert isinstance(e.errors[0], IntegerInvalid)
"""
if cls and not issubclass(cls, Invalid):
raise SchemaError("message can only use subclases of Invalid as custom class")
def decorator(f):
@wraps(f)
def check(msg=None, clsoverride=None):
@wraps(f)
def wrapper(*args, **kwargs):
try:
return f(*args, **kwargs)
except ValueError:
raise (clsoverride or cls or ValueInvalid)(msg or default or 'invalid value')
return wrapper
return check
return decorator
def truth(f):
"""Convenience decorator to convert truth functions into validators.
>>> @truth
... def isdir(v):
... return os.path.isdir(v)
>>> validate = Schema(isdir)
>>> validate('/')
'/'
>>> with raises(MultipleInvalid, 'not a valid value'):
... validate('/notavaliddir')
"""
@wraps(f)
def check(v):
t = f(v)
if not t:
raise ValueError
return v
return check
class Coerce(object):
"""Coerce a value to a type.
If the type constructor throws a ValueError or TypeError, the value
will be marked as Invalid.
Default behavior:
>>> validate = Schema(Coerce(int))
>>> with raises(MultipleInvalid, 'expected int'):
... validate(None)
>>> with raises(MultipleInvalid, 'expected int'):
... validate('foo')
With custom message:
>>> validate = Schema(Coerce(int, "moo"))
>>> with raises(MultipleInvalid, 'moo'):
... validate('foo')
"""
def __init__(self, type, msg=None):
self.type = type
self.msg = msg
self.type_name = type.__name__
def __call__(self, v):
try:
return self.type(v)
except (ValueError, TypeError):
msg = self.msg or ('expected %s' % self.type_name)
raise CoerceInvalid(msg)
def __repr__(self):
return 'Coerce(%s, msg=%r)' % (self.type_name, self.msg)
@message('value was not true', cls=TrueInvalid)
@truth
def IsTrue(v):
"""Assert that a value is true, in the Python sense.
>>> validate = Schema(IsTrue())
"In the Python sense" means that implicitly false values, such as empty
lists, dictionaries, etc. are treated as "false":
>>> with raises(MultipleInvalid, "value was not true"):
... validate([])
>>> validate([1])
[1]
>>> with raises(MultipleInvalid, "value was not true"):
... validate(False)
...and so on.
>>> try:
... validate([])
... except MultipleInvalid as e:
... assert isinstance(e.errors[0], TrueInvalid)
"""
return v
@message('value was not false', cls=FalseInvalid)
def IsFalse(v):
"""Assert that a value is false, in the Python sense.
(see :func:`IsTrue` for more detail)
>>> validate = Schema(IsFalse())
>>> validate([])
[]
>>> with raises(MultipleInvalid, "value was not false"):
... validate(True)
>>> try:
... validate(True)
... except MultipleInvalid as e:
... assert isinstance(e.errors[0], FalseInvalid)
"""
if v:
raise ValueError
return v
@message('expected boolean', cls=BooleanInvalid)
def Boolean(v):
"""Convert human-readable boolean values to a bool.
Accepted values are 1, true, yes, on, enable, and their negatives.
Non-string values are cast to bool.
>>> validate = Schema(Boolean())
>>> validate(True)
True
>>> validate("1")
True
>>> validate("0")
False
>>> with raises(MultipleInvalid, "expected boolean"):
... validate('moo')
>>> try:
... validate('moo')
... except MultipleInvalid as e:
... assert isinstance(e.errors[0], BooleanInvalid)
"""
if isinstance(v, basestring):
v = v.lower()
if v in ('1', 'true', 'yes', 'on', 'enable'):
return True
if v in ('0', 'false', 'no', 'off', 'disable'):
return False
raise ValueError
return bool(v)
class Any(object):
"""Use the first validated value.
:param msg: Message to deliver to user if validation fails.
:param kwargs: All other keyword arguments are passed to the sub-Schema constructors.
:returns: Return value of the first validator that passes.
>>> validate = Schema(Any('true', 'false',
... All(Any(int, bool), Coerce(bool))))
>>> validate('true')
'true'
>>> validate(1)
True
>>> with raises(MultipleInvalid, "not a valid value"):
... validate('moo')
msg argument is used
>>> validate = Schema(Any(1, 2, 3, msg="Expected 1 2 or 3"))
>>> validate(1)
1
>>> with raises(MultipleInvalid, "Expected 1 2 or 3"):
... validate(4)
"""
def __init__(self, *validators, **kwargs):
self.validators = validators
self.msg = kwargs.pop('msg', None)
self._schemas = [Schema(val, **kwargs) for val in validators]
def __call__(self, v):
error = None
for schema in self._schemas:
try:
return schema(v)
except Invalid as e:
if error is None or len(e.path) > len(error.path):
error = e
else:
if error:
raise error if self.msg is None else AnyInvalid(self.msg)
raise AnyInvalid(self.msg or 'no valid value found')
def __repr__(self):
return 'Any([%s])' % (", ".join(repr(v) for v in self.validators))
# Convenience alias
Or = Any
class All(object):
"""Value must pass all validators.
The output of each validator is passed as input to the next.
:param msg: Message to deliver to user if validation fails.
:param kwargs: All other keyword arguments are passed to the sub-Schema constructors.
>>> validate = Schema(All('10', Coerce(int)))
>>> validate('10')
10
"""
def __init__(self, *validators, **kwargs):
self.validators = validators
self.msg = kwargs.pop('msg', None)
self._schemas = [Schema(val, **kwargs) for val in validators]
def __call__(self, v):
try:
for schema in self._schemas:
v = schema(v)
except Invalid as e:
raise e if self.msg is None else AllInvalid(self.msg)
return v
def __repr__(self):
return 'All(%s, msg=%r)' % (
", ".join(repr(v) for v in self.validators),
self.msg
)
# Convenience alias
And = All
class Match(object):
"""Value must be a string that matches the regular expression.
>>> validate = Schema(Match(r'^0x[A-F0-9]+$'))
>>> validate('0x123EF4')
'0x123EF4'
>>> with raises(MultipleInvalid, "does not match regular expression"):
... validate('123EF4')
>>> with raises(MultipleInvalid, 'expected string or buffer'):
... validate(123)
Pattern may also be a _compiled regular expression:
>>> validate = Schema(Match(re.compile(r'0x[A-F0-9]+', re.I)))
>>> validate('0x123ef4')
'0x123ef4'
"""
def __init__(self, pattern, msg=None):
if isinstance(pattern, basestring):
pattern = re.compile(pattern)
self.pattern = pattern
self.msg = msg
def __call__(self, v):
try:
match = self.pattern.match(v)
except TypeError:
raise MatchInvalid("expected string or buffer")
if not match:
raise MatchInvalid(self.msg or 'does not match regular expression')
return v
def __repr__(self):
return 'Match(%r, msg=%r)' % (self.pattern.pattern, self.msg)
class Replace(object):
"""Regex substitution.
>>> validate = Schema(All(Replace('you', 'I'),
... Replace('hello', 'goodbye')))
>>> validate('you say hello')
'I say goodbye'
"""
def __init__(self, pattern, substitution, msg=None):
if isinstance(pattern, basestring):
pattern = re.compile(pattern)
self.pattern = pattern
self.substitution = substitution
self.msg = msg
def __call__(self, v):
return self.pattern.sub(self.substitution, v)
def __repr__(self):
return 'Replace(%r, %r, msg=%r)' % (self.pattern.pattern,
self.substitution,
self.msg)
def _url_validation(v):
parsed = urlparse.urlparse(v)
if not parsed.scheme or not parsed.netloc:
raise UrlInvalid("must have a URL scheme and host")
return parsed
@message('expected a Fully qualified domain name URL', cls=UrlInvalid)
def FqdnUrl(v):
"""Verify that the value is a Fully qualified domain name URL.
>>> s = Schema(FqdnUrl())
>>> with raises(MultipleInvalid, 'expected a Fully qualified domain name URL'):
... s("http://localhost/")
>>> s('http://w3.org')
'http://w3.org'
"""
try:
parsed_url = _url_validation(v)
if "." not in parsed_url.netloc:
raise UrlInvalid("must have a domain name in URL")
return v
except:
raise ValueError
@message('expected a URL', cls=UrlInvalid)
def Url(v):
"""Verify that the value is a URL.
>>> s = Schema(Url())
>>> with raises(MultipleInvalid, 'expected a URL'):
... s(1)
>>> s('http://w3.org')
'http://w3.org'
"""
try:
_url_validation(v)
return v
except:
raise ValueError
@message('not a file', cls=FileInvalid)
@truth
def IsFile(v):
"""Verify the file exists.
>>> os.path.basename(IsFile()(__file__)).startswith('voluptuous.py')
True
>>> with raises(FileInvalid, 'not a file'):
... IsFile()("random_filename_goes_here.py")
"""
return os.path.isfile(v)
@message('not a directory', cls=DirInvalid)
@truth
def IsDir(v):
"""Verify the directory exists.
>>> IsDir()('/')
'/'
"""
return os.path.isdir(v)
@message('path does not exist', cls=PathInvalid)
@truth
def PathExists(v):
"""Verify the path exists, regardless of its type.
>>> os.path.basename(PathExists()(__file__)).startswith('voluptuous.py')
True
>>> with raises(Invalid, 'path does not exist'):
... PathExists()("random_filename_goes_here.py")
"""
return os.path.exists(v)
class Range(object):
"""Limit a value to a range.
Either min or max may be omitted.
Either min or max can be excluded from the range of accepted values.
:raises Invalid: If the value is outside the range.
>>> s = Schema(Range(min=1, max=10, min_included=False))
>>> s(5)
5
>>> s(10)
10
>>> with raises(MultipleInvalid, 'value must be at most 10'):
... s(20)
>>> with raises(MultipleInvalid, 'value must be higher than 1'):
... s(1)
>>> with raises(MultipleInvalid, 'value must be lower than 10'):
... Schema(Range(max=10, max_included=False))(20)
"""
def __init__(self, min=None, max=None, min_included=True,
max_included=True, msg=None):
self.min = min
self.max = max
self.min_included = min_included
self.max_included = max_included
self.msg = msg
def __call__(self, v):
if self.min_included:
if self.min is not None and v < self.min:
raise RangeInvalid(
self.msg or 'value must be at least %s' % self.min)
else:
if self.min is not None and v <= self.min:
raise RangeInvalid(
self.msg or 'value must be higher than %s' % self.min)
if self.max_included:
if self.max is not None and v > self.max:
raise RangeInvalid(
self.msg or 'value must be at most %s' % self.max)
else:
if self.max is not None and v >= self.max:
raise RangeInvalid(
self.msg or 'value must be lower than %s' % self.max)
return v
def __repr__(self):
return ('Range(min=%r, max=%r, min_included=%r,'
' max_included=%r, msg=%r)' % (self.min, self.max,
self.min_included,
self.max_included,
self.msg))
class Clamp(object):
"""Clamp a value to a range.
Either min or max may be omitted.
>>> s = Schema(Clamp(min=0, max=1))
>>> s(0.5)
0.5
>>> s(5)
1
>>> s(-1)
0
"""
def __init__(self, min=None, max=None, msg=None):
self.min = min
self.max = max
self.msg = msg
def __call__(self, v):
if self.min is not None and v < self.min:
v = self.min
if self.max is not None and v > self.max:
v = self.max
return v
def __repr__(self):
return 'Clamp(min=%s, max=%s)' % (self.min, self.max)
class LengthInvalid(Invalid):
pass
class Length(object):
"""The length of a value must be in a certain range."""
def __init__(self, min=None, max=None, msg=None):
self.min = min
self.max = max
self.msg = msg
def __call__(self, v):
if self.min is not None and len(v) < self.min:
raise LengthInvalid(
self.msg or 'length of value must be at least %s' % self.min)
if self.max is not None and len(v) > self.max:
raise LengthInvalid(
self.msg or 'length of value must be at most %s' % self.max)
return v
def __repr__(self):
return 'Length(min=%s, max=%s)' % (self.min, self.max)
class DatetimeInvalid(Invalid):
"""The value is not a formatted datetime string."""
class Datetime(object):
"""Validate that the value matches the datetime format."""
DEFAULT_FORMAT = '%Y-%m-%dT%H:%M:%S.%fZ'
def __init__(self, format=None, msg=None):
self.format = format or self.DEFAULT_FORMAT
self.msg = msg
def __call__(self, v):
try:
datetime.datetime.strptime(v, self.format)
except (TypeError, ValueError):
raise DatetimeInvalid(
self.msg or 'value does not match'
' expected format %s' % self.format)
return v
def __repr__(self):
return 'Datetime(format=%s)' % self.format
class InInvalid(Invalid):
pass
class In(object):
"""Validate that a value is in a collection."""
def __init__(self, container, msg=None):
self.container = container
self.msg = msg
def __call__(self, v):
try:
check = v not in self.container
except TypeError:
check = True
if check:
raise InInvalid(self.msg or 'value is not allowed')
return v
def __repr__(self):
return 'In(%s)' % (self.container,)
class NotInInvalid(Invalid):
pass
class NotIn(object):
"""Validate that a value is not in a collection."""
def __init__(self, container, msg=None):
self.container = container
self.msg = msg
def __call__(self, v):
try:
check = v in self.container
except TypeError:
check = True
if check:
raise NotInInvalid(self.msg or 'value is not allowed')
return v
def __repr__(self):
return 'NotIn(%s)' % (self.container,)
def Lower(v):
"""Transform a string to lower case.
>>> s = Schema(Lower)
>>> s('HI')
'hi'
"""
return str(v).lower()
def Upper(v):
"""Transform a string to upper case.
>>> s = Schema(Upper)
>>> s('hi')
'HI'
"""
return str(v).upper()
def Capitalize(v):
"""Capitalise a string.
>>> s = Schema(Capitalize)
>>> s('hello world')
'Hello world'
"""
return str(v).capitalize()
def Title(v):
"""Title case a string.
>>> s = Schema(Title)
>>> s('hello world')
'Hello World'
"""
return str(v).title()
def Strip(v):
"""Strip whitespace from a string.
>>> s = Schema(Strip)
>>> s(' hello world ')
'hello world'
"""
return str(v).strip()
class DefaultTo(object):
"""Sets a value to default_value if none provided.
>>> s = Schema(DefaultTo(42))
>>> s(None)
42
>>> s = Schema(DefaultTo(list))
>>> s(None)
[]
"""
def __init__(self, default_value, msg=None):
self.default_value = default_factory(default_value)
self.msg = msg
def __call__(self, v):
if v is None:
v = self.default_value()
return v
def __repr__(self):
return 'DefaultTo(%s)' % (self.default_value(),)
class SetTo(object):
"""Set a value, ignoring any previous value.
>>> s = Schema(Any(int, SetTo(42)))
>>> s(2)
2
>>> s("foo")
42
"""
def __init__(self, value):
self.value = default_factory(value)
def __call__(self, v):
return self.value()
def __repr__(self):
return 'SetTo(%s)' % (self.value(),)
class ExactSequenceInvalid(Invalid):
pass
class ExactSequence(object):
"""Matches each element in a sequence against the corresponding element in
the validators.
:param msg: Message to deliver to user if validation fails.
:param kwargs: All other keyword arguments are passed to the sub-Schema
constructors.
>>> from voluptuous import *
>>> validate = Schema(ExactSequence([str, int, list, list]))
>>> validate(['hourly_report', 10, [], []])
['hourly_report', 10, [], []]
>>> validate(('hourly_report', 10, [], []))
('hourly_report', 10, [], [])
"""
def __init__(self, validators, **kwargs):
self.validators = validators
self.msg = kwargs.pop('msg', None)
self._schemas = [Schema(val, **kwargs) for val in validators]
def __call__(self, v):
if not isinstance(v, (list, tuple)):
raise ExactSequenceInvalid(self.msg)
try:
v = type(v)(schema(x) for x, schema in zip(v, self._schemas))
except Invalid as e:
raise e if self.msg is None else ExactSequenceInvalid(self.msg)
return v
def __repr__(self):
return 'ExactSequence([%s])' % (", ".join(repr(v)
for v in self.validators))
class Literal(object):
def __init__(self, lit):
self.lit = lit
def __call__(self, value, msg=None):
if self.lit != value:
raise LiteralInvalid(
msg or '%s not match for %s' % (value, self.lit)
)
else:
return self.lit
def __str__(self):
return str(self.lit)
def __repr__(self):
return repr(self.lit)
class Unique(object):
"""Ensure an iterable does not contain duplicate items.
Only iterables convertable to a set are supported (native types and
objects with correct __eq__).
JSON does not support set, so they need to be presented as arrays.
Unique allows ensuring that such array does not contain dupes.
>>> s = Schema(Unique())
>>> s([])
[]
>>> s([1, 2])
[1, 2]
>>> with raises(Invalid, 'contains duplicate items: [1]'):
... s([1, 1, 2])
>>> with raises(Invalid, "contains duplicate items: ['one']"):
... s(['one', 'two', 'one'])
>>> with raises(Invalid, regex="^contains unhashable elements: "):
... s([set([1, 2]), set([3, 4])])
>>> s('abc')
'abc'
>>> with raises(Invalid, regex="^contains duplicate items: "):
... s('aabbc')
"""
def __init__(self, msg=None):
self.msg = msg
def __call__(self, v):
try:
set_v = set(v)
except TypeError as e:
raise TypeInvalid(
self.msg or 'contains unhashable elements: {0}'.format(e))
if len(set_v) != len(v):
seen = set()
dupes = list(set(x for x in v if x in seen or seen.add(x)))
raise Invalid(
self.msg or 'contains duplicate items: {0}'.format(dupes))
return v
def __repr__(self):
return 'Unique()'
class Set(object):
"""Convert a list into a set.
>>> s = Schema(Set())
>>> s([]) == set([])
True
>>> s([1, 2]) == set([1, 2])
True
>>> with raises(Invalid, regex="^cannot be presented as set: "):
... s([set([1, 2]), set([3, 4])])
"""
def __init__(self, msg=None):
self.msg = msg
def __call__(self, v):
try:
set_v = set(v)
except Exception as e:
raise TypeInvalid(
self.msg or 'cannot be presented as set: {0}'.format(e))
return set_v
def __repr__(self):
return 'Set()'
if __name__ == '__main__':
import doctest
doctest.testmod()