（1）变量与赋值
name = "wanghuafeng"
age = 29
print(name, age)
a和b交换值
a = 3
b = 5
tmp = a
a = b
b = tmp
print(a, b)
变量要求：
a.显式
b.nums_of_words = 19
c.NumsOfWords = 19 #驼峰写法
d."-"在任何语言中都是减号，保留符号
e.数字不能开头，可以在中间和结尾
f.特殊字符不能有，！@￥%……&*（）
g.不能有空格、只能是下划线、数字和字母，关键字不能作为变量
（2）字符编码
ASCII码表（2**8=128个字符）
unicode：统一码、万国码
每一个字符最少用2个字节（16位）来存储，即2**16=65536
utf-8:是针对unicode的可变长度元编码。
它可以使用1~4个字节表示一个符号，根据不同的符号而变化字节长度。
（3）Pycharm修改文件模板
依次打开：File—>Settings—>Editor—>File and Code Templates—>Python Scripts
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Author: WangHuafeng
（4）多行打印
#！/usr/bin/env python
# -*- coding: utf-8 -*-
# Author: wanghuafeng
name = input("input your name:")
age = int(input("input your age:"))
job = input("input your job:")
#print("name is:", name + "\nage is:", age + "\njob is:", job)
msg = """
Information of user %s:
-------------------------
Name: %s
Age : %d
Job : %s
---------End-------------
""" % (name, name, age, job)
print(msg)
%d:整数
%f:浮点数
%s:字符串
代码中的注释
#注释一行最多不超过80个字符
"""
多行注释,
不用每行注释
"""
'''
也可以采用这个注释
'''
（5）隐藏输入密码
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Author: WangHuafeng
import getpass
username = input("请输入用户名：")
password = input("请输入密码：")
print(username, password)
注意：Pycharm上输入密码时没有隐藏，Linux上可以隐藏。
（6）导入模块
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Author: WangHuafeng
import os
cmd_java = os.system("java -version")
print(cmd_java)
注意：导入模块或自己的python文件时不能加.py即：import Hello
（7）Linux上增加tab补全
新建文件tab.py
# python startup file
import sys
import readline
import rlcompleter
import atexit
import os
# tab completion
readline.parse_and_bind('tab: complete')
# history file
histfile = os.path.join(os.environ['HOME'], '.pythonhistory')
try:
readline.read_history_file(histfile)
except IOError:
pass
atexit.register(readline.write_history_file, histfile)
del os, histfile, readline, rlcompleter
保存到/usr/lib/python2.7/dist-packages目录中
python命令行中输入：import tab
即可tab查看命令提示。
（8）if判断
#！/usr/bin/env python
# -*- coding: utf-8 -*-
# Author: wanghuafeng
user = 'wanghuafeng'
passwd = '123456'
username = input("input your name:")
password = input("input your password:")
if user == username and passwd == password:
print("Welcome to login...")
else:
print("用户名或密码错误...")
（9）猜年龄
#！/usr/bin/env python
# -*- coding: utf-8 -*-
# Author: wanghuafeng
age = 22
counter = 0
for i in range(10):
print("counter is :", counter)
if counter < 3:
guess_num = int(input("input your guess num: "))
if guess_num == age:
print("Congratulations! You got it.")
break
elif guess_num > age:
print("Think smaller!")
else:
print("Think Big...")
else:
continue_confirm = input("Do you want to continue because you are stupid:")
if continue_confirm == 'y':
counter = 0
continue
else:
print("Bye.")
break
counter += 1