# 字符串转换，如： => I love you more than i can say

s = 'IloveYOUmoreTHANiCANsay'
def sep_words (s):
    ret = s[0].upper()
    for i in range(1,len(s)):
        if s[i].islower() == s[i-1].isupper():
            ret += ' '
        ret += s[i].lower()
    return ret
print(sep_words(s))