Python String casefold() Method

The String casefold() method converts all characters of the string into lowercase letters and returns a new string.

Syntax

my_string.casefold()

casefold() Parameters

Python String casefold() method does not take any parameters.

casefold() Return Value

Python String casefold() method returns

Examples

Example 1: Casefold a String with casefold() method

The capitalize() method is used to convert the first character of the sentence string to uppercase and the other characters to lowercase.

For example:

my_str = 'tUtORIALReFErEnCe'
result = my_str.casefold()
print(result) # Output: tutorialreference

output

tutorialreference

Example 2: Casefold a String with Non-Alphabetic Characters

If the string has characters that are non-alphabeitc, these characters are kept unchanged while the rest of the string is changed to lowercase.

my_str = '123 Is A Number.'
result = my_str.casefold()
print(result) # Output: 123 is a number.

output

123 is a number.

Example 3: casefold() does Not Change the Original String

The casefold() method returns a new string and does not modify the original string.

For example:

my_str = 'tUtORIALReFErEnCe'
result = my_str.casefold()

print(f"Before casefold(): {my_str}") # Output: Before casefold(): tUtORIALReFErEnCe
print(f"After casefold(): {result}")  # Output: After casefold(): tutorialreference

output

Before casefold(): tUtORIALReFErEnCe
After casefold(): tutorialreference

casefold() method vs lower() method

The casefold() method is similar to the lower() method but it is more aggressive, because it is intended to remove all case distinctions in a string.

For example, the German lowercase letter ß is equivalent to ss. Since it is already lowercase, lower() would do nothing to ß, but casefold() converts it to ss.

my_str = 'Das straße'
result = my_str.casefold()
print(result) # Output: das strasse

my_str = 'Das straße'
result = my_str.lower()
print(result) # Output: das straße

output

das strasse
das straße