【python】 字符串转小写（含汉字等时仍work）

def mylower(str):
outstr = "";
strlen = len(str);
idx = 0;
while idx < strlen:
if ord(str[idx])>0 and ord(str[idx])<= 128:
outstr += str[idx].lower();
idx += 1;
else:
outstr += str[idx:idx+2];
idx += 2; return outstr;