cpython/Lib/encodings/__init__.py

91 lines
2.6 KiB
Python
Raw Normal View History

2000-03-10 19:17:24 -04:00
""" Standard "encodings" Package
Standard Python encoding modules are stored in this package
directory.
Codec modules must have names corresponding to standard lower-case
Marc-Andre's third try at this bulk patch seems to work (except that his copy of test_contains.py seems to be broken -- the lines he deleted were already absent). Checkin messages: New Unicode support for int(), float(), complex() and long(). - new APIs PyInt_FromUnicode() and PyLong_FromUnicode() - added support for Unicode to PyFloat_FromString() - new encoding API PyUnicode_EncodeDecimal() which converts Unicode to a decimal char* string (used in the above new APIs) - shortcuts for calls like int(<int object>) and float(<float obj>) - tests for all of the above Unicode compares and contains checks: - comparing Unicode and non-string types now works; TypeErrors are masked, all other errors such as ValueError during Unicode coercion are passed through (note that PyUnicode_Compare does not implement the masking -- PyObject_Compare does this) - contains now works for non-string types too; TypeErrors are masked and 0 returned; all other errors are passed through Better testing support for the standard codecs. Misc minor enhancements, such as an alias dbcs for the mbcs codec. Changes: - PyLong_FromString() now applies the same error checks as does PyInt_FromString(): trailing garbage is reported as error and not longer silently ignored. The only characters which may be trailing the digits are 'L' and 'l' -- these are still silently ignored. - string.ato?() now directly interface to int(), long() and float(). The error strings are now a little different, but the type still remains the same. These functions are now ready to get declared obsolete ;-) - PyNumber_Int() now also does a check for embedded NULL chars in the input string; PyNumber_Long() already did this (and still does) Followed by: Looks like I've gone a step too far there... (and test_contains.py seem to have a bug too). I've changed back to reporting all errors in PyUnicode_Contains() and added a few more test cases to test_contains.py (plus corrected the join() NameError).
2000-04-05 17:11:21 -03:00
encoding names with hyphens mapped to underscores, e.g. 'utf-8' is
implemented by the module 'utf_8.py'.
2000-03-10 19:17:24 -04:00
Each codec module must export the following interface:
* getregentry() -> (encoder, decoder, stream_reader, stream_writer)
The getregentry() API must return callable objects which adhere to
the Python Codec Interface Standard.
In addition, a module may optionally also define the following
APIs which are then used by the package's codec search function:
* getaliases() -> sequence of encoding name strings to use as aliases
Alias names returned by getaliases() must be standard encoding
names as defined above (lower-case, hyphens converted to
underscores).
2000-03-10 19:17:24 -04:00
Written by Marc-Andre Lemburg (mal@lemburg.com).
(c) Copyright CNRI, All Rights Reserved. NO WARRANTY.
"""#"
import codecs,aliases,exceptions
2000-03-10 19:17:24 -04:00
_cache = {}
_unknown = '--unknown--'
2000-03-10 19:17:24 -04:00
class CodecRegistryError(exceptions.LookupError,
exceptions.SystemError):
pass
2000-03-10 19:17:24 -04:00
def search_function(encoding):
# Cache lookup
entry = _cache.get(encoding,_unknown)
if entry is not _unknown:
2000-03-10 19:17:24 -04:00
return entry
# Import the module
modname = encoding.replace('-', '_')
2000-03-10 19:17:24 -04:00
modname = aliases.aliases.get(modname,modname)
try:
mod = __import__(modname,globals(),locals(),'*')
except ImportError,why:
# cache misses
2000-03-10 19:17:24 -04:00
_cache[encoding] = None
return None
# Now ask the module for the registry entry
try:
entry = tuple(mod.getregentry())
except AttributeError:
entry = ()
if len(entry) != 4:
raise CodecRegistryError,\
'module "%s" (%s) failed to register' % \
(mod.__name__, mod.__file__)
2000-03-10 19:17:24 -04:00
for obj in entry:
if not callable(obj):
raise CodecRegistryError,\
'incompatible codecs in module "%s" (%s)' % \
(mod.__name__, mod.__file__)
2000-03-10 19:17:24 -04:00
# Cache the codec registry entry
2000-03-10 19:17:24 -04:00
_cache[encoding] = entry
# Register its aliases (without overwriting previously registered
# aliases)
2000-03-10 19:17:24 -04:00
try:
codecaliases = mod.getaliases()
except AttributeError:
pass
else:
for alias in codecaliases:
if not aliases.aliases.has_key(alias):
aliases.aliases[alias] = modname
# Return the registry entry
2000-03-10 19:17:24 -04:00
return entry
# Register the search_function in the Python codec registry
codecs.register(search_function)