Python string methods are built-in functions that can be applied to string objects. They allow you to perform various operations on strings such as concatenating, formatting, searching, modifying, and more. Some of the most commonly used string methods are capitalize(), upper(), lower(), strip(), find(), replace(), split(), join(), format(), and many others. These methods help make working with strings in Python easier and more efficient.

Here are 30 of the most important string methods in Python:

• capitalize(): Converts the first character of a string to uppercase.

• casefold(): Converts a string to casefolded format, which is used for case-insensitive operations.

• center(width, fillchar): Returns a string padded with a specified character so that it is centered to a given width.

• count(sub, start, end): Returns the number of non-overlapping occurrences of a substring in a string.

• encode(encoding, errors): Encodes a string into a specified encoding format.

• endswith(suffix, start, end): Returns True if a string ends with a specified suffix.

• expandtabs(tabsize): Replaces tabs in a string with spaces.

• find(sub, start, end): Returns the lowest index in a string where a substring is found.

• format(*args, **kwargs): Formats a string using specified positional and keyword arguments.

• index(sub, start, end): Similar to find(), but raises a ValueError if the substring is not found.

• isalnum(): Returns True if a string is alphanumeric.

• isalpha(): Returns True if a string only contains alphabetical characters.

• isdecimal(): Returns True if a string is a decimal number.

• isdigit(): Returns True if a string only contains digits.

• isidentifier(): Returns True if a string is a valid identifier.

• islower(): Returns True if a string only contains lowercase characters.

• isnumeric(): Returns True if a string only contains numeric characters.

• isprintable(): Returns True if a string contains only printable characters.

• isspace(): Returns True if a string only contains whitespace characters.

• istitle(): Returns True if a string is a titlecased string.

• isupper(): Returns True if a string only contains uppercase characters.

• join(iterable): Concatenates a list of strings using a specified separator.

• ljust(width, fillchar): Returns a string left-justified to a specified width, padded with a specified character.

• lower(): Converts a string to lowercase.

• lstrip(chars): Removes leading characters specified in chars from a string.

• maketrans(x, y): Returns a translation table usable for str.translate().

• partition(sep): Returns a tuple containing the part of a string before a specified separator, the separator itself, and the part after the separator.

• replace(old, new, count): Replaces occurrences of a specified substring with a new string.

• rfind(sub, start, end): Returns the highest index in a string where a substring is found.