listconstructor.py

def square(x):
    return x*x

num=[1,2,3,4]
s=map(square,num)

#Returns a map object
print (s)#Output:<map object at 0x0158E4D8>

print (type(s))#Output:<class 'map'>

#converting map object to list() constructor.
print (list(s))#Output:[1, 4, 9, 16]