Python 之 七个Python小技巧

三分钟学会七个Python小技巧

for循环中的else条件

numbers = [2, 4, 6, 8, 1]
for number in numbers:
    if number % 2 == 1:
        print(number)
        break
else:
    print('没有数字是奇数')

从列表中获取元素,定义多个变量

my_list = [1,2,3,4,5]
a, b, c, d, e = my_list
print(a)
print(b)
print(c)
print(d)
print(e)

使用heapq模块，获取列表中n个最大或最小的元素

import heapq

scores = [51, 33, 64, 87, 91, 75, 15, 49, 33, 82]
print(heapq.nsmallest(5, scores))
print(heapq.nlargest(2, scores))

将列表中的所有元素作为参数传递给函数

my_list = [1,2,3,4]


def sum_of_elements(*arg):
    total = 0
    for i in arg:
        total += i
    return total


print(sum_of_elements(*my_list))

列表推导式

numbers = [1,2,3,4,5]
s_numbers = [num * num for num in numbers]
print(s_numbers)

重复字符串：从列表中获取元素,定义多个变量

my_list = [1,2,3,4,5]
a, b, c, d, e = my_list
print(a)
print(b)
print(c)
print(d)
print(e)
print('-' * 100)
# 4、将列表中的所有元素作为参数传递给函数
my_list = [1,2,3,4]
def sum_of_elements(*arg):
    total = 0
    for i in arg:
        total += i
    return total
print(sum_of_elements(*my_list))

字符串转列表或者字典

list_str = '[1,2,3,4,5]'
dict_str = '{"A": "啊", "B": "不"}'
int_str = '1'
print(eval(list_str))
print(type(eval(list_str)))
print(eval(dict_str))
print(type(eval(dict_str)))
print(eval(int_str))
print(type(eval(int_str)))



# json数据转字典

import json

print(type(json.loads(dict_str)))

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