Python中迭代相关的简单介绍（附代码）

# map经常配合lambdas来使用

items = [1, 2, 3, 4, 5]

squared = list(map(lambda x: x**2, items))

# 用于循环调用一列表的函数

def multiply(x):

        return (x*x)

def add(x):

        return (x+x)

funcs = [multiply, add]

for i in range(5):

    value = map(lambda x: x(i), funcs)

    print(list(value))

# Output:

# [0, 0]

# [1, 2]

# [4, 4]

# [9, 6]

# [16, 8]

number_list = range(-5, 5)

less_than_zero = filter(lambda x: x < 0, number_list)

print(list(less_than_zero)) 

# Output: [-5, -4, -3, -2, -1]

# 配置从哪个数字开始枚举

my_list = ['apple', 'banana', 'grapes', 'pear']

for c, value in enumerate(my_list, 1):

    print(c, value)

# 输出:

(1, 'apple')

(2, 'banana')

(3, 'grapes')

(4, 'pear')

for item in container:

    if search_something(item):

        # Found it!

        process(item)

        break

else:

    # Didn't find anything..

    not_found_in_container()

from functools import reduce

product = reduce( (lambda x, y: x * y), [1, 2, 3, 4] )

# Output: 24