what does lower do in python code example

Example 1: python lowercase

// turn to lower/upper
string = string.upper()
string = string.lower()

// check if all letter are lower or upper
string.islower()
string.isupper()

Example 2: python convert string to lowercase

# By Alan W. Smith and Petar Ivanov
s = "Kilometer"
print(s.lower())

Example 3: python string lowercase

startString = "TeST StrIng"
lowerCaseString = startString.lower()
print(lowerCaseString)
# Output -> "test string"