map()

# def  multiply_by2(item):
#     return item*2
    
#     # new_list=[]
#     # for item in li:
#     #     new_list.append(item*2)
#     # return new_list
        
# print(list(map(multiply_by2,[1,2,3])))

my_list=[1,2,3]
def  multiply_by2(item):
    return item*2
    
print(list(map(multiply_by2,my_list)))
print(my_list) #it doesn't change the list