利用map和reduce编写一个str2float函数,把字符串'123.456'转换成浮点数123.456
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from functools import reduce
def str2float(s):
return reduce ( lambda x,y:x + int2dec(y), map (str2int,s.split( '.' )))
def char2num(s):
return { '0' : 0 , '1' : 1 , '2' : 2 , '3' : 3 , '4' : 4 , '5' : 5 , '6' : 6 , '7' : 7 , '8' : 8 , '9' : 9 }[s]
def str2int(s):
return reduce ( lambda x,y:x * 10 + y, map (char2num,s))
def intLen(i):
return len ( '%d' % i)
def int2dec(i):
return i / ( 10 * * intLen(i))
print (str2float( '123.456' ))
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以上就是本代码的全部内容了,希望对大家学习Python能够有所帮助。