How to convert a string to uppercase or lowercase?

The built-in string methods .upper() and .lower() are used.

# Example of converting to uppercase
my_string = "hello world"
upper_string = my_string.upper()
# upper_string is now "HELLO WORLD"

# Example of converting to lowercase
another_string = "HELLO PYTHON"
lower_string = another_string.lower()
# lower_string is now "hello python"

Comparison table:

Method	Description	Input example	Result
.upper()	Converts all characters in the string to uppercase.	"test STRING"	"TEST STRING"
.lower()	Converts all characters in the string to lowercase.	"Test STRING"	"test string"