01-模块中的__all__的作用
__all__ = ['函数','全局变量','类'] 方便使用
from 模块 import * -- 使用
02-包、__init__.py的作用
import sys
sys.argv
name = '33'
print('欢迎 %s 的到来'%name )
***
eval函数,是转换成之前转换的格式。
***
列表生成
a = [i for i in range(10,19)]
>>> a = [i for i in range(10,19)]
>>> a
[10, 11, 12, 13, 14, 15, 16, 17, 18]
>>> a = [i for i in range(10,19) if i%2==0]
>>> a
[10, 12, 14, 16, 18]
>>>
>>> a = [i for i in range(10,19) for j in range(2)]
>>> a
[10, 10, 11, 11, 12, 12, 13, 13, 14, 14, 15, 15, 16, 16, 17, 17, 18, 18]