map() function returns a map object(which is an iterator) of the results after applying the given function to each item of a given iterable (list, tuple etc.)
Syntax :
map(fun, iter)
Parameters :
fun : It is a function to which map passes each element of given iterable.
iter : It is a iterable which is to be mapped.
NOTE : You can pass one or more iterable to the map() function.
Returns :
Returns a list of the results after applying the given function to each item of a given iterable (list, tuple etc.)
NOTE : The returned value from map() (map object) then can be passed to functions like list() (to create a list), set() (to create a set) .
CODE 1
# Python program to demonstrate working # of map. # Return double of n def addition(n): return n + n # We double all numbers using map() numbers = ( 1 , 2 , 3 , 4 ) result = map (addition, numbers) print ( list (result)) |
Output :
[2, 4, 6, 8]
CODE 2
We can also use lambda expressions with map to achieve above result.
# Double all numbers using map and lambda numbers = ( 1 , 2 , 3 , 4 ) result = map ( lambda x: x + x, numbers) print ( list (result)) |
Output :
[2, 4, 6, 8]
CODE 3
# Add two lists using map and lambda numbers1 = [ 1 , 2 , 3 ] numbers2 = [ 4 , 5 , 6 ] result = map ( lambda x, y: x + y, numbers1, numbers2) print ( list (result)) |
Output :
[5, 7, 9]
CODE 4
# List of strings l = [ 'sat' , 'bat' , 'cat' , 'mat' ] # map() can listify the list of strings individually test = list ( map ( list , l)) print (test) |
Output :
[['s', 'a', 't'], ['b', 'a', 't'], ['c', 'a', 't'], ['m', 'a', 't']]
Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics.
To begin with, your interview preparations Enhance your Data Structures concepts with the Python DS Course.