python内置函数

Posted 2021-07-17 小小菜_v

Python 开发中使用的函数总结

1、lambda匿名函数

time_list = [{"year": 2021, "month": 5, "day": 20}, {"year": 2021, "month": 5, "day": 21}]
# 使用lambda 函数对字典s中的value以元组的形式添加到列表n中
time_group = lambda s, n: n.append((s.get('year'), s.get('month'), s.get('day')))

s_list = []
# 循环遍历time_list
[time_group(i, s_list) for i in list(time_list )]
# 输出处理后的结果
print(s_list)

2、sorted() 排序

sorted（iterable, key=None, reverse=False）
# list()转换为列表， set() 集合去重
sorted(list(set(s_list)))
# zfill()自动补充0将字符串的位数改为2位数
sorted(dict_, key=lambda x: '-'.join(
									[str(x['year']),
									[str(x['month']).zfill(2),
									[str(x['day']).zfill(2)
									]))

3、filter()

example_list = [5, 0, 6, 1, 2, 7, 3, 4]
result_list = filter(lambda x: x % 2 == 1, example_list)
print(list(result_list))

输出

"C:\\Program Files\\Python39\\python.exe" E:/caicai/tests.py
[5, 1, 7, 3]

Process finished with exit code 0

4、Interval()

"""
Interval是一个区间库，可以给出范围值判断是否在范围中
"""
from interval import Interval

time_ = time.strftime("%H:%m")
if time_ in Interval("15:00", "16:00"):
    print("Now time is ", time_)

"C:\\Program Files\\Python39\\python.exe" E:/caicai/tests.py
Now time is 15:05

Process finished with exit code 0

5、ast.literal_eval()

"""将字符串带有字典列表的关键符号进行转换"""
import ast
dict_ = ast.literal_eval('{"name":"Bob"}')
print(dict_)
print(type(dict_))
print(isinstance(dict_, dict))

"C:\\Program Files\\Python39\\python.exe" E:/caicai/tests.py
{'name': 'Bob'}
<class 'dict'>
True

Process finished with exit code 0