Python学习笔记-字符串与注释

OSX从Pthon 2.7升级到3.8

1，官网下载最新安装包安装

2，执行认证文件command

3，执行设置path command

4，设置默认python

在terminal里运行open  ~/.bash_profile，打开~/.bash_profile，直接修改文件保存，重启Terminal。

source ~/.bash_profile

# Setting PATH for Python 3.8

# The original version is saved in .bash_profile.pysave

export PATH=$PATH:/Library/Frameworks/Python.framework/Versions/3.8/bin:

alias python="/Library/Frameworks/Python.framework/Versions/3.8/bin/python3.8"

Print练习

>>> print("hello world")
hello world
>>>
>>>
>>> ms="good morning"
>>> print(ms)
good morning
>>>
>>>
>>> ms=
>>> print(ms)

字符串操作

title：首字母大写

upper:全大写

lower:全小写

strip:去掉两头空格

lstrip:去掉左边空格

rstrip:去掉右边空格

+：链接字符串

>>> ms="li xiaobin"
>>>
>>> print(ms.upper())
LI XIAOBIN
>>>
>>> print(ms.lower())
li xiaobin
>>>
>>> print(ms.title())
Li Xiaobin
>>>
>>> ms=" li xiao bin "
>>>
>>> print(ms.strip())
li xiao bin
>>>
>>> print(ms)
 li xiao bin
>>> print(ms.lstrip())
li xiao bin
>>>
>>> print(ms.rstrip())
 li xiao bin
>>>
>>>
>>> print('li'+ms)
li li xiao bin
>>> 

代码注释

# hello world
print("hello ¥n li xiaobin")

如果多行注释可以使用如下方法：

'''
many lines hello world

by lixiaobin
'''
print("hello ¥n li xiaobin")