Python comes with a built-in method on all String types, by calling lower() on a String, you can immediately lower the case of that String.

An example to LowerCase a String in Python

words = "These are some WORDS"
words.lower() # <- How to lowerCase a String
# output: these are some words
"These are some WORDS".lower() # <- How to lowerCase a String
# output: these are some words

Now let’s try and see how it may look in a coding challenge:

The challenge

Given a string s, return the string after replacing every uppercase letter with the same lowercase letter.

Example 1:

Input: s = "Hello"
Output: "hello"

Example 2:

Input: s = "here"
Output: "here"

Example 3:

Input: s = "LOVELY"
Output: "lovely"

Constraints:

  • 1 <= s.length <= 100
  • s consists of printable ASCII characters.

Our solution in Python code

class Solution:
    def toLowerCase(self, s: str) -> str:
        return s.lower()