The map() function in Python3! ! !

The prototype of the map function is map(function, iterable, …), and its return result is a list.
The function is a function name, and iterable is an iterable object (can be a list, string, tuple~~~~~)
For example:

a=(1,2,3,4,5)
b=[1,2,3,4,5]
c="NBA"

Q=map(str,a)
A=map(str,b)
W=map(str,c)

print(Q)
print(A)
print(W)

输出：
['1', '2', '3', '4', '5']
['1', '2', '3', '4', '5']
['N','B','A']

For example, to calculate the sum of the digits of a natural number:

num = input(' 请输入一个自然数：')#输入一个自然数
print(sum(map(int,num))) #把自然数的每一位都变成int形式，在用sum()函数求和