>>> codec_list = ["base64_codec", "bz2_codec", "hex_codec", "idna", "mbcs", "palmos", "punycode", "quopri_codec", "raw_unicode_escape", "rot_13", "string_escape", "unicode_escape", "unicode_internal", "uu_codec", "zlib_codec", "zip"]
>>> for n in codec_list:
...     try:
...             print a.decode(n)
...     except:
...             print "Error occured while decoding with ", n
... 
bHmZBMuZ
Error occured while decoding with  bz2_codec
Error occured while decoding with  hex_codec
YkhtWkJNdVo=
Error occured while decoding with  mbcs
YkhtWkJNdVo=
Error occured while decoding with  punycode
YkhtWkJNdVo
YkhtWkJNdVo=
LxugJxWAqIb=
YkhtWkJNdVo=
YkhtWkJNdVo=
Error occured while decoding with  unicode_internal
Error occured while decoding with  uu_codec
Error occured while decoding with  zlib_codec
Error occured while decoding with  zip
>>>