map in python 3

1# Python program to demonstrate working 
2# of map. 
3  
4# Return double of n 
5def addition(n): 
6    return n + n 
7  
8# We double all numbers using map() 
9numbers = (1, 2, 3, 4) 
10result = map(addition, numbers) 
11print(list(result))

1#generate a list from map iterable with lambda expression
2list( map(lambda x: x*2, numeros) )

1map(function_to_apply, list_of_inputs)

1map(function, iterable, ...)

1# Let's define general python function
2>>> def doubleOrNothing(num):
3...     return num * 2
4
5# now use Map on it.
6>>> map(doubleOrNothing, [1,2,3,4,5])
7<map object at 0x7ff5b2bc7d00>
8
9# apply built-in list method on Map Object
10>>> list(map(doubleOrNothing, [1,2,3,4,5])
11[2, 4, 6, 8, 10]
12
13# using lambda function
14>>> list(map(lambda x: x*2, [1,2,3,4,5]))
15[2, 4, 6, 8, 10]

1from multiprocessing import Pool
2
3def test( v ):
4    print(v)
5    return v
6
7if __name__ == '__main__':
8    with Pool(2) as p:
9        print(p.map(test, range(5)))