| Case Conversion | capitalize() | Converts the first character to uppercase. |
| lower() | Converts all characters to lowercase. |
| upper() | Converts all characters to uppercase. |
| title() | Converts the first character of each word to uppercase. |
| swapcase() | Swaps the case of all characters. |
| Alignment | center(width, char) | Centers the string in a field of specified width. |
| ljust(width, char) | Left-aligns the string in a field of specified width. |
| rjust(width, char) | Right-aligns the string in a field of specified width. |
| zfill(width) | Pads the string with zeros on the left. |
| Search & Replace | find(substring, start, end) | Returns the index of the first occurrence of the substring (or -1 if not found). |
| rfind(substring, start, end) | Returns the index of the last occurrence of the substring (or -1 if not found). |
| index(substring, start, end) | Like find(), but raises ValueError if not found. |
| rindex(substring, start, end) | Like rfind(), but raises ValueError if not found. |
| replace(old, new, count) | Replaces occurrences of old with new. |
| count(substring, start, end) | Returns the number of occurrences of a substring. |
| String Validation | isalnum() | Returns True if all characters are alphanumeric. |
| isalpha() | Returns True if all characters are alphabetic. |
| isdigit() | Returns True if all characters are digits. |
| isdecimal() | Returns True if all characters are decimals. |
| isnumeric() | Returns True if all characters are numeric. |
| isidentifier() | Returns True if the string is a valid Python identifier. |
| islower() | Returns True if all characters are lowercase. |
| isupper() | Returns True if all characters are uppercase. |
| istitle() | Returns True if the string is in title case. |
| isspace() | Returns True if all characters are whitespace. |
| isascii() | Returns True if all characters are ASCII. |
| Trimming | strip(chars) | Removes leading and trailing characters. |
| lstrip(chars) | Removes leading characters. |
| rstrip(chars) | Removes trailing characters. |
| Splitting & Joining | split(sep, maxsplit) | Splits the string into a list of substrings. |
| rsplit(sep, maxsplit) | Splits the string from the right into a list of substrings. |
| splitlines(keepends) | Splits the string into lines. |
| join(iterable) | Joins the elements of an iterable into a single string. |
| Encoding & Formatting | encode(encoding, errors) | Encodes the string into bytes. |
| format(*args, **kwargs) | Formats the string. |
| format_map(mapping) | Formats the string using a mapping. |
| maketrans(mapping) | Creates a translation table. |
| translate(table) | Translates the string using a translation table. |
| String Composition | partition(sep) | Splits the string into three parts: before, separator, and after. |
| rpartition(sep) | Like partition() but splits from the right. |
| startswith(prefix, start, end) | Returns True if the string starts with the specified prefix. |
| endswith(suffix, start, end) | Returns True if the string ends with the specified suffix. |
| Miscellaneous | casefold() | Converts the string to casefolded lowercase (more aggressive than lower()). |
| expandtabs(tabsize) | Replaces tabs with spaces. |
| removeprefix(prefix) | Removes the specified prefix (introduced in Python 3.9). |
| removesuffix(suffix) | Removes the specified suffix (introduced in Python 3.9). |