Base62，,#filename:ba

Base62，,#filename:ba

#filename:base62.py__all__ = ('encode', 'decode',)LETTERS, SIZE = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ',62DICT = dict( (char,index) for index,char in enumerate(LETTERS) )def div_util(num, dividend):    while True:        num,index = divmod(num,dividend)        yield index        if num == 0:            returndecode = lambda str_ : sum( DICT[char]*(SIZE**(index)) for index,char in enumerate(str_[::-1]) )encode = lambda num : ''.join( LETTERS[index] for index in div_util(num, SIZE) )[::-1]#该片段来自于http://byrx.net