全局变量

apple=10
b=20
def fun():
    global b
    b=apple
    return b+40
print(apple)
print('b pass:',b)
print(fun())
print('b now:',b)

输出结果

10
b pass: 20
50
b now: 10

安装模块
Mac: 终端环境里
- 安装：sudo pip3 install numpy
- 卸载：sudo pip3 uninstall numpy
- 更新：sudo pip3 install -U bumpy

文件读写
程序

text = 'one line\ntwo line.\nthree line.'

file = open('new_file.txt','w') 
file.write(text)
file.close()

输出结果

one line
two line.
three line.

16