String Functions

strings col1000 python Strings

STRINGS ARE IMMUTABLE SO THERE IS NO FUNCTION THAT CHANGES A STRING IN PLACE
S=S.FUNC() WILL MAKE A NEW STRING IS THE ONLY WAY TO UPDATE THE STRING

1. Case Modification Methods

• upper() / lower()

  • Syntax: s.upper(), s.lower()

  • Explanation: Converts all characters to uppercase or lowercase.

• capitalize() / title()

  • Syntax: s.capitalize(), s.title()

  • Explanation: Capitalizes the first character of the string, or the first letter of every word, respectively.

• swapcase()

  • Syntax: s.swapcase()

  • Explanation: Inverts the case of all characters (lowercase becomes uppercase and vice versa).

2. Searching & Validation Methods

• find(sub) / count(sub)

  • Syntax: s.find("text"), s.count("text")

  • Explanation: find() returns the lowest index where a substring is found (or -1), while count() returns how many times it appears.

• startswith(sub) / endswith(sub)

  • Syntax: s.startswith("A"), s.endswith("Z")

  • Explanation: Returns True if the string starts or ends with the specified substring.

• isdigit() / isalpha() / isalnum()

  • Syntax: s.isdigit(), s.isalpha()

  • Explanation: Boolean checks to see if characters are purely digits, purely alphabetical, or alphanumeric.

3. Modification & Formatting Methods

• strip()

  • Syntax: s.strip()

  • Explanation: Removes leading and trailing whitespace (variants include lstrip() and rstrip()).

• replace(old, new)

  • Syntax: s= s.replace("old", "new")

  • Explanation: Replaces all occurrences of a specified substring with a new one.

• split(sep) / join(iterable)

  • Syntax: s.split(","), ",".join(list)

  • Explanation: split() breaks a string into a list based on a separator; join() merges an iterable of strings into a single string using the string as a separator.

Note: Similar to lists, strings do not use explicit attributes for metadata, but you can inspect them using built-in functions like len(s) to get the character count.