The map () function in Python

The map () function built into Python works to browse all the elements of an iterable (list, tuple, dictionary .) through a given function and returns a list of results after execution.

So the syntax of the map () function like, what parameters it has and how to use it? Invites you to read the track.

Syntax of map () function in Python

 map(function, iterable, .)

The parameters of the map () function

function The function executes for each element in the iterable.
iterable : a list, tuple, dictionary . want to browse.

You can pass multiple iterablecho map () functions.

Return value from map ()

The map () function browses all iterable elements through the function and returns a list of results after execution.

The value returned from map () is called map object. This object can be passed to list () functions (to create lists in Python), or set () (to create a new set of elements) .

Example 1: How does map () work?

 def binhphuong(n): return n*n # viet boi TipsMake.com number = (25, 100, 225, 400) ketqua = map(binhphuong, number) # chuyen map object thanh list print(list(ketqua))

When you run the program, the output will be:

 [25, 100, 225, 400]

In the above example, every element in the original tuple is square.

Example 2: How to use lambda functions with map ()

Because map () always needs parameters to pass, lambda functions are often used with map ().

In Python, lambda functions or anonymous functions are defined without a name. If normal functions are defined using the keyword def , then anonymous functions are defined using the keyword lambda .

Read more: Anonymous functions, Lambda in Python.

 # viet boi TipsMake.com number = (5, 10, 15, 20) result = map(lambda x: x*x, number) # chuyen map object thanh list sobinhphuong = list(result) print(sobinhphuong)

Running the program, the result is returned:

 [25, 100, 225, 400]

The result is no different from example 1 .

Example 3: Passing multiple iterator parameters to map () using lambda

In this example, the corresponding elements of the two lists are added.

 num1 = [4, 5, 6] num2 = [5, 6, 7] result = map(lambda n1, n2: n1+n2, num1, num2) print(list(result))

The result is:

 [9, 11, 13]

You should read it

May be interested

Help () function in Python
the built-in help () function in python is used to display documents and invoke the help system of modules, functions, classes, keywords ...
Sum () function in Python
the built-in function sum () in python returns the sum of all numbers in iterable.
The slice () function in Python
the slice () function in python returns a slice object that helps you determine how to cut an existing string.
The chr () function in Python
in python, the chr () function returns a character (a string) from an integer that represents the unicode of the returned character.
The iter () function in Python
continuing with the topic of python's built-in functions, the article will introduce you to the iter () function with the syntax, usage as well as specific examples. invites you to read the track.
The pow () function in Python
the pow () function built into python returns the value of x with the power of y (xy). if there is a third parameter, the function returns x to the power y, the module z.
The reversed () function in Python
the reversed () function is one of the built-in functions in python, used to reverse the original string returning the iterator.
Built-in Python functions
in the previous article, you learned that python has a basic function type, one is a built-in function, two are user-defined functions. today, we will learn about a list of python's built-in functions.
Exec () function in Python
the exec () function used to execute python programs dynamically can be string or object code. how does exec () function syntax, what parameters do it have, and how is it used? invites you to read the track.
The compile () function in Python
the compile () function returns a code object in python from the specified source. so how to use compile () function? please find out in this article.