python 第一天
****************第一天*****************
****铺垫****
linux 安装python3
yum install -y gcc gcc-c++
yum install readline-devel
yum install zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel readline-devel tk-devel gdbm-devel db4-devel libpcap-devel xz-devel
echo /usr/local/lib >> /etc/ld.so.conf.d/local.conf
ldconfig
tar -xvf Python-3.5.1.tgz
cd Python-3.5.1/
./configure --prefix=/usr/local/python3
make
make install
cd /usr/local/python3/
cp bin/python3 /usr/bin #支持全局变量
随地调用
python3
Python 3.5.1 (default, May 9 2016, 21:08:00)
[GCC 4.8.3 20140911 (Red Hat 4.8.3-9)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>>
1.字符集：
概念：
python 2.0 只支持ascii,需要声明字符集,需要解析器
python 3.0 默认编码unicode ，默认支持中文，不需要关心字符编码，不需要解析器
ascii 码: 转换标准：转为01计算机码
字符编码
演变史
ascii
Unicode
UTF-8
使用：
python 2.0
#!/usr/bin/env python
#_*_coding:utf-8_*_
print("王明虎")
print("Hello World! \n牛逼")
python 3.0
print("王明虎")
#!/usr/bin/env python
print("Hello World!")
print("Hello World! \nwmh")
2.变量
概念：经常变的值,一般为小写
test:
x = 2
y = 3
print(x + y)
3.引号
凡是单引或双引都是字符
name = 'wmh'
age = 21
三引号
python 开发规范每一行最多不能超过80个字符
print """
fdsalkjfljdsaffdjsfdsalkfsafsa
jfdlksajflksafdjlsaffafdsaf
kjflksajfdlsajfldsafljsaflja
"""
4.用户输入
2.0 用raw_input
3.0 用input
使用:
python 2
user_input = raw_input("your name:")
print user_input
python 3
user_input = input("input your name:")
print ("is:",user_input)
多input同步输出1,调用变量msg
#!/usr/bin/env python
#-*- coding:utf-8 -*-
# Author:Minghu Wang
name = input("Please input your name:")
age = int(input("Please input your age:")) #字符转数字，因为3.0，默认变量全是字符，不加会报错
job = input("Please input your job:")
msg='''
Personal information of %s:
------------start-------------
Name: %s
Age : %d
Job : %s
------------End---------------
''' % (name,name,age,job)
print(msg)
多input同步输出2，直接print
#!/usr/bin/env python
#-*- coding:utf-8 -*-
# Author:Minghu Wang
name = input("Please input your name:")
age = int(input("Please input your age:")) #字符转数字，因为3.0，默认变量全是字符，不加会报错
job = input("Please input your job:")
print('''
Personal information of %s:
------------start-------------
Name: %s
Age : %d
Job : %s
------------End---------------
''' % (name,name,age,job))
密文输入：只能在LINUX使用
vi test_pass.py
import getpass
username = input("username:")
password = getpass.getpass("password:")
print(username,password)
5.模块：
概念：内置模块，第三方模块
os模块，使用命令
import os
os.system("df -h")
os.mkdir('yourdir')
cmd_res = os.popen('df -h').read()
print(cmd_res)
每一个脚本就是一个模块
当前目录调用脚本即模块test_pass.py
import test_pass
6.TAB补全
python tab补全模块，保存tab.py
#!/usr/bin/env python
# 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
import sys
print(sys.path) 找到目录存tab.py,以后在那个目录都能使用table补全
>>> print(sys.path)
['', '/usr/local/python3/lib/python35.zip', '/usr/local/python3/lib/python3.5', '/usr/local/python3/lib/python3.5/plat-linux',
'/usr/local/python3/lib/python3.5/lib-dynload', '/usr/local/python3/lib/python3.5/site-packages']
在/usr/local/python3/lib/python3.5 目录存放tab.py
7.条件判断
if else
使用：
用户相等测试
#!/usr/bin/env python
#-*- coding:utf-8 -*-
# Author:Minghu Wang
user = 'alex'
passwd ='alex3714'
username = input("username:")
password = input("password:")
if user == username:
print("username is correct...")
密码用户登录验证
#!/usr/bin/env python
#-*- coding:utf-8 -*-
# Author:Minghu Wang
user = 'alex'
passwd ='alex3714'
username = input("username:")
password = input("password:")
if user == username:
print("username is correct...")
if passwd == password:
print("welcome login")
else:
print("password is invalid...")
else:
print("连用户名都没蒙对，滚粗。。。。。")
密码用户同时相等
#!/usr/bin/env python
#-*- coding:utf-8 -*-
# Author:Minghu Wang
user = 'alex'
passwd ='alex3714'
username = input("username:")
password = input("password:")
if user == username and passwd ==password:
print("Welcome login")
else:
print("Invalid username or password..")
猜年龄1
#!/usr/bin/env python
#-*- coding:utf-8 -*-
# Author:Minghu Wang
age = 22
guess_num = int(input("input your guess num:"))
if guess_num == age:
print("Congratulations you got it.")
elif guess_num > age:
print("Think smaller!")
else:
print("Think Big...")
for i range(10):
print(i)
猜3次报次数多
#!/usr/bin/env python
#-*- coding:utf-8 -*-
# Author:Minghu Wang
age = 22
for i in range(10):
if i < 3:
guess_num = int(input("input your guess num:"))
if guess_num == age:
print("Congratulations you got it.")
break #不往后走了，跳出整个loop
elif guess_num > age:
print("Think smaller!")
else:
print("Think Big...")
else:
print("too many attempts...bye")
break
猜3次，提示是否继续
#!/usr/bin/env python
#-*- coding:utf-8 -*-
# Author:Minghu Wang
age = 22
counter = 0
for i in range(10):
if counter < 3:
guess_num = int(input("input your guess num:"))
if guess_num == age:
print("Congratulations you got it.")
break #不往后走了，跳出整个loop
elif guess_num > age:
print("Think smaller!")
else:
print("Think Big...")
else:
counter_confirm = input("Do you want to continue because you are stupid:")
if counter_confirm == 'y':
counter = 0
continue
else:
print("bye")
break
counter +=1 #counter = counter + 1
