709. To Lower Case-转换成小写字母

Implement function ToLowerCase() that has a string parameter str, and returns the same string in lowercase.

Example 1:
Input: "Hello"
Output: "hello"

Example 2:
Input: "here"
Output: "here"

Example 3:
Input: "LOVELY"
Output: "lovely"

Solution in python:

class Solution:
    def toLowerCase(self, str: str) -> str:
        result = ""
        for item in str:
            if 'A' <= item <= 'Z':
                result += chr(ord(item)+32)
            else:
                result += item
        return result