len()
len() is a Python function in the Built-in Functions category. Returns the length (number of items) of an object. Works with sequences, collections, and strings. The syntax is len(s). Parameters: s — a sequence or collection. Returns: Integer length. A typical example: len([1, 2, 3]) # 3
len("hello") # 5. A close sibling is print(), which prints objects to the text stream, separated by `sep` and followed by `end`. A close sibling is range(), which returns an immutable sequence of numbers. Commonly used in for loops. A close sibling is type(), which returns the type of an object, or creates a new type with three arguments. A close sibling is int(), which converts a number or string to an integer, or returns 0 if no arguments. More about this category: Python's built-in functions available without importing — print, len, range, map, and more. For a broader walkthrough, read the Built-in Functions guide.