map( )会根据提供的函数对指定序列做映射

lst = ['1', '2', '3', '4', '5', '6']
print(lst)
lst_int = map(lambda x: int(x) ** 2, lst)
print(list(lst_int))  # [1, 4, 9, 16, 25, 36]

lst = map(str, [i for i in range(10)])
print(list(lst))  # ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']

lst_2 = map(int, range(5))
print(list(lst_2))  # [0, 1, 2, 3, 4]

list1 = [1, 2, 3, 4, 5]
def func(x):
    return x ** 2
result = map(func, list1)
print(result)  # <map object at 0x0000000003DE5518>
print(list(result))  # [1, 4, 9, 16, 25]


list1 = [1, 2, 3, 4, 5]
list2 = [1, 2, 3, 4, 5, 6]
list3 = [1, 2, 3, 4, 5, 6, 7]
def func1(x, y, z):
    return x + y + z
def func2(x, y, z):
    return x, y, z
result1 = map(func1, list1, list2, list3)
print(result1)   # <map object at 0x0000000003DE5C88>
print(list(result1))  # [3, 6, 9, 12, 15]
result2 = map(func2, list1, list2, list3)
print(result2)  # <map object at 0x0000000003DE5940>
print(list(result2))  # [(1, 1, 1), (2, 2, 2), (3, 3, 3), (4, 4, 4), (5, 5, 5)]

map( )会根据提供的函数对指定序列做映射
map(func， *iterables) 创建一个迭代器，用来自序列的参数依次传入函数。当序列迭代器耗尽时停止。

map()返回的是一个迭代器，直接打印map()的结果是返回的一个对象