added doc string for stream

tensorwatch/stream.py

@@ -7,6 +7,21 @@ from . import utils
 from .lv_types import StreamItem
 
 class Stream:
+    """
+    Stream allows you to write values into it. One stream can subscribe to many streams. When a value is
+    written in the stream, all subscribers also gets that value written into them (the from_steam parameter
+    is set to the source stream).
+
+    You can read values from a stream by calling read_all method. This will yield values as someone or subscribed streams are
+    writing into the stream. You can also load all values from the stream. The default stream won't load anything but
+    derived streams like file may load all values from the file and write into themselves.
+
+    You can think of stream as a pipe that can be chained to other pipees. As value is put in pipe, it travels through
+    connected pipes. The read_all method is like a tap that you can use to read values from the pipe. The load method is
+    for specialized streams that may generate values in that pipe.
+
+    Stream class supports full multi-threading.
+    """
     def __init__(self, stream_name:str=None, console_debug:bool=False):
         self._subscribers = weakref.WeakSet()
         self._subscribed_to = weakref.WeakSet()