Mirror
/
cpython
mirror of https://github.com/python/cpython
4
1
Fork 0
Code Issues Releases Wiki Activity

M.-A. Lemburg <mal@lemburg.com>: 

Added more documentation. Clarified some existing comments.
This commit is contained in:
Fred Drake 2000-04-13 14:11:21 +00:00
parent 4e998bc658
commit 49fd1077bc
1 changed files with 40 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

44
Lib/codecs.py
View File

@ -231,10 +231,13 @@ class StreamReader(Codec):
""" Read one line from the input stream and return the """ Read one line from the input stream and return the
decoded data. decoded data.
Note: Unlike the .readlines() method, line breaking must Note: Unlike the .readlines() method, this method inherits
be implemented by the underlying stream's .readline() the line breaking knowledge from the underlying stream's
method -- there is currently no support for line breaking .readline() method -- there is currently no support for
using the codec decoder due to lack of line buffering. line breaking using the codec decoder due to lack of line
buffering. Sublcasses should however, if possible, try to
implement this method using their own knowledge of line
breaking.
size, if given, is passed as size argument to the stream's size, if given, is passed as size argument to the stream's
.readline() method. .readline() method.
@ -288,6 +291,14 @@ class StreamReader(Codec):
class StreamReaderWriter: class StreamReaderWriter:
""" StreamReaderWriter instances allow wrapping streams which
work in both read and write modes.
The design is such that one can use the factory functions
returned by the codec.lookup() function to contruct the
instance.
"""
# Optional attributes set by the file wrappers below # Optional attributes set by the file wrappers below
encoding = 'unknown' encoding = 'unknown'
@ -346,6 +357,21 @@ class StreamReaderWriter:
class StreamRecoder: class StreamRecoder:
""" StreamRecoder instances provide a frontend - backend
view of encoding data.
They use the complete set of APIs returned by the
codecs.lookup() function to implement their task.
Data written to the stream is first decoded into an
intermediate format (which is dependent on the given codec
combination) and then written to the stream using an instance
of the provided Writer class.
In the other direction, data is read from the stream using a
Reader instance and then return encoded data to the caller.
"""
# Optional attributes set by the file wrappers below # Optional attributes set by the file wrappers below
data_encoding = 'unknown' data_encoding = 'unknown'
file_encoding = 'unknown' file_encoding = 'unknown'
@ -452,6 +478,11 @@ def open(filename, mode, encoding=None, errors='strict', buffering=1):
buffering has the same meaning as for the builtin open() API. buffering has the same meaning as for the builtin open() API.
It defaults to line buffered. It defaults to line buffered.
The returned wrapped file object provides an extra attribute
.encoding which allows querying the used encoding. This
attribute is only available if an encoding was specified as
parameter.
""" """
if encoding is not None and \ if encoding is not None and \
'b' not in mode: 'b' not in mode:
@ -488,6 +519,11 @@ def EncodedFile(file, data_encoding, file_encoding=None, errors='strict'):
data_encoding and file_encoding are added to the wrapped file data_encoding and file_encoding are added to the wrapped file
object as attributes .data_encoding and .file_encoding resp. object as attributes .data_encoding and .file_encoding resp.
The returned wrapped file object provides two extra attributes
.data_encoding and .file_encoding which reflect the given
parameters of the same name. The attributes can be used for
introspection by Python programs.
""" """
if file_encoding is None: if file_encoding is None:
file_encoding = data_encoding file_encoding = data_encoding