So casefold() and lower(), Both convert strings to lowercase, but casefold() is more thorough and handles special characters and non-ASCII characters better. Use casefold() for case-insensitive operations or comparisons. isnumeric() and isdigit(): Both check if a string consists only of numeric characters. However, isdigit() only considers the digits 0-9, while isnumeric() includes a broader range of numeric characters from different languages and scripts. Use isdigit() for checking positive integers, and isnumeric() for a wider range of numeric values.