# -*- coding:utf-8 -*-

"""

将驼峰命名法字符串转换成下划线命名法

eg. GetItem ---> get_item

getIT ----> get_it

"""

def changeStr(param):

rest = []

for k,v in enumerate(param):

if v.isupper():

rest.append(k)

print rest

nrest = len(rest)

nparam = len(param)

res = ""

if rest[0] == 0:

for i in range(0,len(rest)-1):

res += param[rest[i]:rest[i+1]]

if rest[i+1] - rest[i] == 1:

continue

res += "_"

res += param[rest[nrest-1]:nparam]

else:

res += param[0:rest[0]]

res += "_"

for i in range(0,len(rest)-1):

res += param[rest[i]:rest[i+1]]

if rest[i+1] - rest[i] == 1:

continue

res += "_"

res += param[rest[nrest-1]:nparam]

return res.lower()

if __name__ == "__main__":

print changeStr("heGetItEmQY")

print changeStr("GetItem")