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cpython/Lib/encodings/zlib_codec.py

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This patch changes the way the string .encode() method works slightly and introduces a new method .decode(). The major change is that strg.encode() will no longer try to convert Unicode returns from the codec into a string, but instead pass along the Unicode object as-is. The same is now true for all other codec return types. The underlying C APIs were changed accordingly. Note that even though this does have the potential of breaking existing code, the chances are low since conversion from Unicode previously took place using the default encoding which is normally set to ASCII rendering this auto-conversion mechanism useless for most Unicode encodings. The good news is that you can now use .encode() and .decode() with much greater ease and that the door was opened for better accessibility of the builtin codecs. As demonstration of the new feature, the patch includes a few new codecs which allow string to string encoding and decoding (rot13, hex, zip, uu, base64). Written by Marc-Andre Lemburg. Copyright assigned to the PSF.
2001-05-15 09:00:02 -03:00
""" Python 'zlib_codec' Codec - zlib compression encoding
Unlike most of the other codecs which target Unicode, this codec
will return Python string objects for both encode and decode.
Written by Marc-Andre Lemburg (mal@lemburg.com).
"""
import codecs
import zlib # this codec needs the optional zlib module !
### Codec APIs
def zlib_encode(input,errors='strict'):
""" Encodes the object input and returns a tuple (output
object, length consumed).
errors defines the error handling to apply. It defaults to
'strict' handling which is the only currently supported
error handling for this codec.
"""
assert errors == 'strict'
output = zlib.compress(input)
return (output, len(input))
def zlib_decode(input,errors='strict'):
""" Decodes the object input and returns a tuple (output
object, length consumed).
input must be an object which provides the bf_getreadbuf
buffer slot. Python strings, buffer objects and memory
mapped files are examples of objects providing this slot.
errors defines the error handling to apply. It defaults to
'strict' handling which is the only currently supported
error handling for this codec.
"""
assert errors == 'strict'
output = zlib.decompress(input)
return (output, len(input))
class Codec(codecs.Codec):
Patch #462635 by Andrew Kuchling correcting bugs in the new codecs -- the self argument does matter for Python functions (it does not for C functions which most other codecs use).
2001-09-20 07:33:38 -03:00
def encode(self, input, errors='strict'):
return zlib_encode(input, errors)
def decode(self, input, errors='strict'):
return zlib_decode(input, errors)
This patch changes the way the string .encode() method works slightly and introduces a new method .decode(). The major change is that strg.encode() will no longer try to convert Unicode returns from the codec into a string, but instead pass along the Unicode object as-is. The same is now true for all other codec return types. The underlying C APIs were changed accordingly. Note that even though this does have the potential of breaking existing code, the chances are low since conversion from Unicode previously took place using the default encoding which is normally set to ASCII rendering this auto-conversion mechanism useless for most Unicode encodings. The good news is that you can now use .encode() and .decode() with much greater ease and that the door was opened for better accessibility of the builtin codecs. As demonstration of the new feature, the patch includes a few new codecs which allow string to string encoding and decoding (rot13, hex, zip, uu, base64). Written by Marc-Andre Lemburg. Copyright assigned to the PSF.
2001-05-15 09:00:02 -03:00
class StreamWriter(Codec,codecs.StreamWriter):
pass
Whitespace normalization.
2002-08-08 17:19:19 -03:00
This patch changes the way the string .encode() method works slightly and introduces a new method .decode(). The major change is that strg.encode() will no longer try to convert Unicode returns from the codec into a string, but instead pass along the Unicode object as-is. The same is now true for all other codec return types. The underlying C APIs were changed accordingly. Note that even though this does have the potential of breaking existing code, the chances are low since conversion from Unicode previously took place using the default encoding which is normally set to ASCII rendering this auto-conversion mechanism useless for most Unicode encodings. The good news is that you can now use .encode() and .decode() with much greater ease and that the door was opened for better accessibility of the builtin codecs. As demonstration of the new feature, the patch includes a few new codecs which allow string to string encoding and decoding (rot13, hex, zip, uu, base64). Written by Marc-Andre Lemburg. Copyright assigned to the PSF.
2001-05-15 09:00:02 -03:00
class StreamReader(Codec,codecs.StreamReader):
pass
### encodings module API
def getregentry():
return (zlib_encode,zlib_decode,StreamReader,StreamWriter)