jcconv, Japanese Characters CONVerter, interconvert hiragana, katakana, half-width kana. This module also treat 'half/wide number', 'half/wide alphabet'.
Since 0.2.0, check_hira, check_kata, check_half functions were added. you can check if string consists of characters you specified.
IMPOTANT: In current version, this works only with utf-8 encoding.
Simple example of usage is followings
>>> from jcconv import *
>>> print hira2kata('あいうえお') # hiragana to katakana
アイウエオ
>>> print kata2hira('カタカナ') # katakana to hiragana
かたかな
>>> print half2hira('ﾊﾝｶｸｶﾀｶﾅ') # half-width kana to hiragana
はんかくかたかな
>>> print half2wide('hello jcconv') # half-width alphabet to wide-width
ｈｅｌｌｏ ｊｃｃｏｎｖ
>>> print wide2half('ＷＩＤＥ') # wide-width alphabet to half-width
wide