Python map() function

The map() function in Python is a built-in function used to apply a given function to each item in an iterable (like a list, tuple, etc.) and return a new iterable (a map object) with the results.

Syntax

• function: A function to apply to each element of the iterable.
• iterable: One or more iterables to be processed.
• If multiple iterables are passed, the function must accept as many arguments as there are iterables, and it is applied element-wise.

Returns

A map object, which is an iterator. You can convert it to a list, tuple, or another collection type as needed.

Examples

Single Iterable

Multiple Iterables

Using a Predefined Function

Lazy Evaluation

The map() function doesn’t execute until explicitly iterated over:

Key Points

• Performance: map() is often faster than list comprehensions for applying simple functions, as it doesn’t require the overhead of constructing a list in memory.
• Readable Alternative: In some cases, list comprehensions are preferred for readability:
  python

  Copy code

  squared = [x**2 for x in numbers]

• Compatibility: If you need compatibility across Python 2 and 3, be aware that map() in Python 3 returns a lazy iterator, whereas in Python 2, it directly returns a list.