Add IANA character set aliases to the encodings alias dictionary

and make alias lookup lazy.

Note that only those IANA character set aliases were added for which
we actually have codecs in the encodings package.

2 files changed, 355 insertions, 106 deletions

diff --git a/Lib/encodings/__init__.py b/Lib/encodings/__init__.py
index 3830954..65f5c9c 100644
--- a/Lib/encodings/__init__.py
+++ b/Lib/encodings/__init__.py
@@ -4,8 +4,8 @@
     directory.
 
     Codec modules must have names corresponding to standard lower-case
-    encoding names with hyphens mapped to underscores, e.g. 'utf-8' is
-    implemented by the module 'utf_8.py'.
+    encoding names with hyphens and periods mapped to underscores,
+    e.g. 'utf-8' is implemented by the module 'utf_8.py'.
 
     Each codec module must export the following interface:
 
@@ -28,10 +28,11 @@ Written by Marc-Andre Lemburg (mal@lemburg.com).
 
 """#"
 
-import codecs,aliases,exceptions
+import codecs,exceptions
 
 _cache = {}
 _unknown = '--unknown--'
+_import_tail = ['*']
 
 class CodecRegistryError(exceptions.LookupError,
                          exceptions.SystemError):
@@ -40,19 +41,37 @@ class CodecRegistryError(exceptions.LookupError,
 def search_function(encoding):
     
     # Cache lookup
-    entry = _cache.get(encoding,_unknown)
+    entry = _cache.get(encoding, _unknown)
     if entry is not _unknown:
         return entry
 
-    # Import the module
+    # Import the module:
+    #
+    # First look in the encodings package, then try to lookup the
+    # encoding in the aliases mapping and retry the import using the
+    # default import module lookup scheme with the alias name.
+    #
     modname = encoding.replace('-', '_')
-    modname = aliases.aliases.get(modname,modname)
+    modname = modname.replace('.', '_')
     try:
-        mod = __import__(modname,globals(),locals(),'*')
+        mod = __import__('encodings.' + modname,
+                         globals(), locals(), _import_tail)
     except ImportError,why:
+        import aliases
+        modname = aliases.aliases.get(modname, _unknown)
+        if modname is not _unknown:
+            try:
+                mod = __import__(modname,
+                                 globals(), locals(), _import_tail)
+            except ImportError,why:
+                mod = None
+        else:
+            mod = None
+    if mod is None:
         # cache misses
         _cache[encoding] = None
         return None
+        
     
     # Now ask the module for the registry entry
     try:
@@ -79,6 +98,7 @@ def search_function(encoding):
     except AttributeError:
         pass
     else:
+        import aliases
         for alias in codecaliases:
             if not aliases.aliases.has_key(alias):
                 aliases.aliases[alias] = modname
diff --git a/Lib/encodings/aliases.py b/Lib/encodings/aliases.py
index d6101da..b6882ae 100644
--- a/Lib/encodings/aliases.py
+++ b/Lib/encodings/aliases.py
@@ -4,108 +4,337 @@
     map encodings names to module names.
 
     Note that the search function converts the encoding names to lower
-    case and replaces hyphens with underscores *before* performing the
-    lookup.
+    case and replaces hyphens and periods with underscores *before*
+    performing the lookup.
+
+    Contents:
+
+        The following aliases dictionary contains mappings of all IANA
+        character set names for which the Python core library provides
+        codecs. In addition to these, a few Python specific codec
+        aliases have also been added.
+
+    About the CJK codec aliases:
+
+        The codecs for these encodings are not distributed with the
+        Python core, but are included here for reference, since the
+        locale module relies on having these aliases available.
 
 """
 aliases = {
 
-    # Latin-1
-    'latin': 'latin_1',
-    'latin1': 'latin_1',
-    
-    # UTF-7
-    'utf7': 'utf_7',
-    'u7': 'utf_7',
-    
-    # UTF-8
-    'utf': 'utf_8',
-    'utf8': 'utf_8',
-    'u8': 'utf_8',
-    'utf8@ucs2': 'utf_8',
-    'utf8@ucs4': 'utf_8',
-    
-    # UTF-16
-    'utf16': 'utf_16',
-    'u16': 'utf_16',
-    'utf_16be': 'utf_16_be',
-    'utf_16le': 'utf_16_le',
-    'unicodebigunmarked': 'utf_16_be',
-    'unicodelittleunmarked': 'utf_16_le',
-
-    # ASCII
-    'us_ascii': 'ascii',
-    'ansi_x3.4_1968': 'ascii', # used on Linux
-    '646': 'ascii',            # used on Solaris
-
-    # EBCDIC
-    'ebcdic_cp_us': 'cp037',
-    'ibm039': 'cp037',
-    'ibm1140': 'cp1140',
-    
-    # ISO
-    '8859': 'latin_1',
-    'iso8859': 'latin_1',
-    'iso8859_1': 'latin_1',
-    'iso_8859_1': 'latin_1',
-    'iso_8859_10': 'iso8859_10',
-    'iso_8859_13': 'iso8859_13',
-    'iso_8859_14': 'iso8859_14',
-    'iso_8859_15': 'iso8859_15',
-    'iso_8859_2': 'iso8859_2',
-    'iso_8859_3': 'iso8859_3',
-    'iso_8859_4': 'iso8859_4',
-    'iso_8859_5': 'iso8859_5',
-    'iso_8859_6': 'iso8859_6',
-    'iso_8859_7': 'iso8859_7',
-    'iso_8859_8': 'iso8859_8',
-    'iso_8859_9': 'iso8859_9',
-
-    # Mac
-    'maclatin2': 'mac_latin2',
-    'maccentraleurope': 'mac_latin2',
-    'maccyrillic': 'mac_cyrillic',
-    'macgreek': 'mac_greek',
-    'maciceland': 'mac_iceland',
-    'macroman': 'mac_roman',
-    'macturkish': 'mac_turkish',
-
-    # Windows
-    'windows_1251': 'cp1251',
-    'windows_1252': 'cp1252',
-    'windows_1254': 'cp1254',
-    'windows_1255': 'cp1255',
-
-    # MBCS
-    'dbcs': 'mbcs',
-
-    # Code pages
-    '437': 'cp437',
-
-    # CJK
-    #
-    # The codecs for these encodings are not distributed with the
-    # Python core, but are included here for reference, since the
-    # locale module relies on having these aliases available.
-    #
-    'jis_7': 'jis_7',
-    'iso_2022_jp': 'jis_7',
-    'ujis': 'euc_jp',
-    'ajec': 'euc_jp',
-    'eucjp': 'euc_jp',
-    'tis260': 'tactis',
-    'sjis': 'shift_jis',
-
-    # Content transfer/compression encodings
-    'rot13': 'rot_13',
-    'base64': 'base64_codec',
-    'base_64': 'base64_codec',
-    'zlib': 'zlib_codec',
-    'zip': 'zlib_codec',
-    'hex': 'hex_codec',
-    'uu': 'uu_codec',
-    'quopri': 'quopri_codec',
-    'quotedprintable': 'quopri_codec',
-    'quoted_printable': 'quopri_codec',
+    # ascii codec
+    '646'                : 'ascii',
+    'ansi_x3_4_1968'     : 'ascii',
+    'ansi_x3_4_1986'     : 'ascii',
+    'cp367'              : 'ascii',
+    'csascii'            : 'ascii',
+    'ibm367'             : 'ascii',
+    'iso646_us'          : 'ascii',
+    'iso_646_irv:1991'   : 'ascii',
+    'iso_ir_6'           : 'ascii',
+    'us'                 : 'ascii',
+    'us_ascii'           : 'ascii',
+
+    # base64_codec codec
+    'base64'             : 'base64_codec',
+    'base_64'            : 'base64_codec',
+
+    # cp037 codec
+    'csibm037'           : 'cp037',
+    'ebcdic_cp_ca'       : 'cp037',
+    'ebcdic_cp_nl'       : 'cp037',
+    'ebcdic_cp_us'       : 'cp037',
+    'ebcdic_cp_wt'       : 'cp037',
+    'ibm037'             : 'cp037',
+    'ibm039'             : 'cp037',
+
+    # cp1026 codec
+    'csibm1026'          : 'cp1026',
+    'ibm1026'            : 'cp1026',
+
+    # cp1140 codec
+    'ibm1140'            : 'cp1140',
+
+    # cp1250 codec
+    'windows_1250'       : 'cp1250',
+
+    # cp1251 codec
+    'windows_1251'       : 'cp1251',
+
+    # cp1252 codec
+    'windows_1252'       : 'cp1252',
+
+    # cp1253 codec
+    'windows_1253'       : 'cp1253',
+
+    # cp1254 codec
+    'windows_1254'       : 'cp1254',
+
+    # cp1255 codec
+    'windows_1255'       : 'cp1255',
+
+    # cp1256 codec
+    'windows_1256'       : 'cp1256',
+
+    # cp1257 codec
+    'windows_1257'       : 'cp1257',
+
+    # cp1258 codec
+    'windows_1258'       : 'cp1258',
+
+    # cp424 codec
+    'csibm424'           : 'cp424',
+    'ebcdic_cp_he'       : 'cp424',
+    'ibm424'             : 'cp424',
+
+    # cp437 codec
+    '437'                : 'cp437',
+    'cspc8codepage437'   : 'cp437',
+    'ibm437'             : 'cp437',
+
+    # cp500 codec
+    'csibm500'           : 'cp500',
+    'ebcdic_cp_be'       : 'cp500',
+    'ebcdic_cp_ch'       : 'cp500',
+    'ibm500'             : 'cp500',
+
+    # cp775 codec
+    'cspc775baltic'      : 'cp775',
+    'ibm775'             : 'cp775',
+
+    # cp850 codec
+    '850'                : 'cp850',
+    'cspc850multilingual' : 'cp850',
+    'ibm850'             : 'cp850',
+
+    # cp852 codec
+    '852'                : 'cp852',
+    'cspcp852'           : 'cp852',
+    'ibm852'             : 'cp852',
+
+    # cp855 codec
+    '855'                : 'cp855',
+    'csibm855'           : 'cp855',
+    'ibm855'             : 'cp855',
+
+    # cp857 codec
+    '857'                : 'cp857',
+    'csibm857'           : 'cp857',
+    'ibm857'             : 'cp857',
+
+    # cp860 codec
+    '860'                : 'cp860',
+    'csibm860'           : 'cp860',
+    'ibm860'             : 'cp860',
+
+    # cp861 codec
+    '861'                : 'cp861',
+    'cp_is'              : 'cp861',
+    'csibm861'           : 'cp861',
+    'ibm861'             : 'cp861',
+
+    # cp862 codec
+    '862'                : 'cp862',
+    'cspc862latinhebrew' : 'cp862',
+    'ibm862'             : 'cp862',
+
+    # cp863 codec
+    '863'                : 'cp863',
+    'csibm863'           : 'cp863',
+    'ibm863'             : 'cp863',
+
+    # cp864 codec
+    'csibm864'           : 'cp864',
+    'ibm864'             : 'cp864',
+
+    # cp865 codec
+    '865'                : 'cp865',
+    'csibm865'           : 'cp865',
+    'ibm865'             : 'cp865',
+
+    # cp866 codec
+    '866'                : 'cp866',
+    'csibm866'           : 'cp866',
+    'ibm866'             : 'cp866',
+
+    # cp869 codec
+    '869'                : 'cp869',
+    'cp_gr'              : 'cp869',
+    'csibm869'           : 'cp869',
+    'ibm869'             : 'cp869',
+
+    # hex_codec codec
+    'hex'                : 'hex_codec',
+
+    # iso8859_10 codec
+    'csisolatin6'        : 'iso8859_10',
+    'iso_8859_10'        : 'iso8859_10',
+    'iso_8859_10:1992'   : 'iso8859_10',
+    'iso_ir_157'         : 'iso8859_10',
+    'l6'                 : 'iso8859_10',
+    'latin6'             : 'iso8859_10',
+
+    # iso8859_13 codec
+    'iso_8859_13'        : 'iso8859_13',
+
+    # iso8859_14 codec
+    'iso_8859_14'        : 'iso8859_14',
+    'iso_8859_14:1998'   : 'iso8859_14',
+    'iso_celtic'         : 'iso8859_14',
+    'iso_ir_199'         : 'iso8859_14',
+    'l8'                 : 'iso8859_14',
+    'latin8'             : 'iso8859_14',
+
+    # iso8859_15 codec
+    'iso_8859_15'        : 'iso8859_15',
+
+    # iso8859_2 codec
+    'csisolatin2'        : 'iso8859_2',
+    'iso_8859_2'         : 'iso8859_2',
+    'iso_8859_2:1987'    : 'iso8859_2',
+    'iso_ir_101'         : 'iso8859_2',
+    'l2'                 : 'iso8859_2',
+    'latin2'             : 'iso8859_2',
+
+    # iso8859_3 codec
+    'csisolatin3'        : 'iso8859_3',
+    'iso_8859_3'         : 'iso8859_3',
+    'iso_8859_3:1988'    : 'iso8859_3',
+    'iso_ir_109'         : 'iso8859_3',
+    'l3'                 : 'iso8859_3',
+    'latin3'             : 'iso8859_3',
+
+    # iso8859_4 codec
+    'csisolatin4'        : 'iso8859_4',
+    'iso_8859_4'         : 'iso8859_4',
+    'iso_8859_4:1988'    : 'iso8859_4',
+    'iso_ir_110'         : 'iso8859_4',
+    'l4'                 : 'iso8859_4',
+    'latin4'             : 'iso8859_4',
+
+    # iso8859_5 codec
+    'csisolatincyrillic' : 'iso8859_5',
+    'cyrillic'           : 'iso8859_5',
+    'iso_8859_5'         : 'iso8859_5',
+    'iso_8859_5:1988'    : 'iso8859_5',
+    'iso_ir_144'         : 'iso8859_5',
+
+    # iso8859_6 codec
+    'arabic'             : 'iso8859_6',
+    'asmo_708'           : 'iso8859_6',
+    'csisolatinarabic'   : 'iso8859_6',
+    'ecma_114'           : 'iso8859_6',
+    'iso_8859_6'         : 'iso8859_6',
+    'iso_8859_6:1987'    : 'iso8859_6',
+    'iso_ir_127'         : 'iso8859_6',
+
+    # iso8859_7 codec
+    'csisolatingreek'    : 'iso8859_7',
+    'ecma_118'           : 'iso8859_7',
+    'elot_928'           : 'iso8859_7',
+    'greek'              : 'iso8859_7',
+    'greek8'             : 'iso8859_7',
+    'iso_8859_7'         : 'iso8859_7',
+    'iso_8859_7:1987'    : 'iso8859_7',
+    'iso_ir_126'         : 'iso8859_7',
+
+    # iso8859_8 codec
+    'csisolatinhebrew'   : 'iso8859_8',
+    'hebrew'             : 'iso8859_8',
+    'iso_8859_8'         : 'iso8859_8',
+    'iso_8859_8:1988'    : 'iso8859_8',
+    'iso_ir_138'         : 'iso8859_8',
+
+    # iso8859_9 codec
+    'csisolatin5'        : 'iso8859_9',
+    'iso_8859_9'         : 'iso8859_9',
+    'iso_8859_9:1989'    : 'iso8859_9',
+    'iso_ir_148'         : 'iso8859_9',
+    'l5'                 : 'iso8859_9',
+    'latin5'             : 'iso8859_9',
+
+    # jis_7 codec
+    'csiso2022jp'        : 'jis_7',
+    'iso_2022_jp'        : 'jis_7',
+
+    # koi8_r codec
+    'cskoi8r'            : 'koi8_r',
+
+    # latin_1 codec
+    '8859'               : 'latin_1',
+    'cp819'              : 'latin_1',
+    'csisolatin1'        : 'latin_1',
+    'ibm819'             : 'latin_1',
+    'iso8859'            : 'latin_1',
+    'iso_8859_1'         : 'latin_1',
+    'iso_8859_1:1987'    : 'latin_1',
+    'iso_ir_100'         : 'latin_1',
+    'l1'                 : 'latin_1',
+    'latin'              : 'latin_1',
+    'latin1'             : 'latin_1',
+
+    # mac_cyrillic codec
+    'maccyrillic'        : 'mac_cyrillic',
+
+    # mac_greek codec
+    'macgreek'           : 'mac_greek',
+
+    # mac_iceland codec
+    'maciceland'         : 'mac_iceland',
+
+    # mac_latin2 codec
+    'maccentraleurope'   : 'mac_latin2',
+    'maclatin2'          : 'mac_latin2',
+
+    # mac_roman codec
+    'macroman'           : 'mac_roman',
+
+    # mac_turkish codec
+    'macturkish'         : 'mac_turkish',
+
+    # mbcs codec
+    'dbcs'               : 'mbcs',
+
+    # quopri_codec codec
+    'quopri'             : 'quopri_codec',
+    'quoted_printable'   : 'quopri_codec',
+    'quotedprintable'    : 'quopri_codec',
+
+    # rot_13 codec
+    'rot13'              : 'rot_13',
+
+    # tactis codec
+    'tis260'             : 'tactis',
+
+    # utf_16 codec
+    'u16'                : 'utf_16',
+    'utf16'              : 'utf_16',
+
+    # utf_16_be codec
+    'unicodebigunmarked' : 'utf_16_be',
+    'utf_16be'           : 'utf_16_be',
+
+    # utf_16_le codec
+    'unicodelittleunmarked' : 'utf_16_le',
+    'utf_16le'           : 'utf_16_le',
+
+    # utf_7 codec
+    'u7'                 : 'utf_7',
+    'utf7'               : 'utf_7',
+
+    # utf_8 codec
+    'u8'                 : 'utf_8',
+    'utf'                : 'utf_8',
+    'utf8'               : 'utf_8',
+    'utf8@ucs2'          : 'utf_8',
+    'utf8@ucs4'          : 'utf_8',
+
+    # uu_codec codec
+    'uu'                 : 'uu_codec',
+
+    # zlib_codec codec
+    'zip'                : 'zlib_codec',
+    'zlib'               : 'zlib_codec',
 
 }