python

print(）格式输入

print(format(val,format_modifier))

val: 值

format_modifier 格式学

print(format(12.34567,'6.2f'))

6 输入占位

3 精度 小数点 后几位

百分号 格式化输出

print(format(0.346,'.2%'))

输入语句

re=raw_input(prompt)

prompt 提示字符

re 为返回值

>>> age = raw_input ( 'your age : ' )
your age : 23
>>> print (age)
23
>>> age = int (age)
>>> age = int ( raw_input ( 'plz input your age' ))
plz input your age 23
>>> print age
23
>>> type (age)
< type 'int' >

age =int（age） 字符串转换成整型

int 整型

float 浮点型数据

id 函数

>>> print x
12
>>> id (x)
38687280
>>> print x
12
>>> x = 13
>>> print x
13
>>> id (x)
38687256
>>> x = 12
>>> print x
12
>>> id (x)
38687280
>>> y = 13
>>> print y
13
>>> id (y)
38687256
>>>指向 内存 一样

python 变量  不是内容变 指向内存单元的变

>>> x = 12
>>> y = 12.5
>>> z = 'www.baidu.com'
>>> print x
12
>>> print y
12.5
>>> print z
www.baidu.com
>>> type (x)
< type 'int' >
>>> type (y)
< type 'float' >
>>> type (z)
< type 'str' >

python 函数

字符函数库

>>> s = 'baidu'

>>> s.islower()

True

小写函数

替换函数

>>> s4 ='abadsadsadasbab111111111'

>>> s4.replace('ab','AB')

'ABadsadsadasbAB111111111'

默认字符库

import math

引入数学函数库

>>> import math

>>> val=math.sin(3.14/6)

>>> print val

0.499770102643

>>> math.pi

3.1415926535897931

>>> val=math.sin(math.pi /6)

>>> print val

0.5

>>> 3*3*3*3

81

>>> math.pow(3,4)

81.0

pow函数 3的4次方

>>> 3*3*3*3*3*3*3

2187

>>> math.pow(3,7)

2187.0

>>> 3**7

2187

import os

加载操作系统模块

>>> import os

>>> os.getcwd()

'/root'

>>> import socket

>>> baiduip=socket.gethostbyname('www.baidu.com')

>>> print baiduip

115.239.210.26

获得某主机ip地址 网络库

输入quit（）

第三方提供的函数库

httplib2

[root@ceshi ~] # yum install python-setuptools
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: mirrors. 163.com
* extras: mirrors.grandcloud.cn
* updates: mirrors.grandcloud.cn
Setting up Install Process
Resolving Dependencies
- - > Running transaction check
- - - > Package python - setuptools.noarch 0 : 0.6 . 10 - 3.el6 set to be updated
- - > Finished Dependency Resolution
Dependencies Resolved
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
Package                  Arch          Version               Repository   Size
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
Installing:
python - setuptools        noarch         0.6 . 10 - 3.el6 base         336 k
Transaction Summary
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
Install       1 Package(s)
Upgrade       0 Package(s)
Total download size: 336 k
Installed size: 1.5 M
Is this ok [y / N]: y
Downloading Packages:
python - setuptools - 0.6 . 10 - 3.el6 .noarch.rpm                | 336 kB     00 : 00
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
Installing     : python - setuptools - 0.6 . 10 - 3.el6 .noarch                     1 / 1
Installed:
python - setuptools.noarch 0 : 0.6 . 10 - 3.el6
Complete!

import urllib
import webbrowser
url = 'http://www.163.com'
content = urllib.urlopen(url).read()
open ( '163.com.html' , 'w' ).write(content)
webbrowser.open_new_tab( '163.com.html' )

[root@ceshi ~] # easy_install httplib2
Searching for httplib2
Reading http: / / pypi.python.org / simple / httplib2 /
Reading http: / / code.google.com / p / httplib2 /
Best match: httplib2 0.8
Downloading http: / / httplib2.googlecode.com / files / httplib2 - 0.8 . zip
Processing httplib2 - 0.8 . zip
Running httplib2 - 0.8 / setup.py - q bdist_egg - - dist - dir / tmp / easy_install - jLdE50 / httplib2 - 0.8 / egg - dist - tmp - jb2a6G
zip_safe flag not set ; analyzing archive contents...
httplib2.__init__: module references __file__
Adding httplib2 0.8 to easy - install.pth file
Installed / usr / lib / python2. 6 / site - packages / httplib2 - 0.8 - py2. 6.egg
Processing dependencies for httplib2
Finished processing dependencies for httplib2

安装第三方函数库

或者使用

pip install
先yum一下python-pip包

然后用pip install安装好了

进行测试

[root@ceshi ~] # python
Python 2.6 . 6 (r266: 84292 , Nov 22 2013 , 12 : 16 : 22 )
[GCC 4.4 . 7 20120313 (Red Hat 4.4 . 7 - 4 )] on linux2
Type "help" , "copyright" , "credits" or "license" for more information.
>>> import httplib2
>>>

[root@ceshi ~] # python 1.py
Entry programme
hello the cruel world!
www.baidu.com
Leave programme
[root@ceshi ~] # vi 1.py
#!/usr/bin/python
def test_a():
print 'hello the cruel world!'
print 'www.baidu.com'
print 'Entry programme'
test_a()
print 'Leave programme'

自定义函数 注意要有冒号和缩进

[root@ceshi ~] # vi 1.py
#!/usr/bin/python
def test_a():
print 'hello the cruel world!'
print 'www.baidu.com'
def test_b(va11,va12):
print va11,
print va12
print 'Entry programme'
test_a()
test_b( 12 , 13 )
test_b( 'www.baidu.com' , 'python' )
test_a()
print 'Leave programme'

返回值 return

#!/usr/bin/python
def test_a():
print 'hello the cruel world!'
print 'www.baidu.com'
def test_b(va11,va12):
print va11,
print va12
def test_c(n1,n2):
print n1,
print n2
n = n1 + n2
return n
print 'Entry programme'
test_a()
test_b( 12 , 13 )
test_b( 'www.baidu.com' , 'python' )
sum = test_c( 100 , 102 )
print 'sum = ' , sum
print 'Leave programme'

Entry programme

hello the cruel world!

www.baidu.com

12 13

www.baidu.com python

100 102

sum =  202

Leave programme

#!/usr/bin/python
def test_a():
print 'hello the cruel world!'
print 'www.baidu.com'
def test_b(va11,va12):
print va11,
print va12
def test_c(n1,n2):
print n1,
print n2
n = n1 + n2
return n
def test_d(n1,n2):
print n1,
print n2
n = n1 + n2
m = n1 * n2
p = n1 - n2
e = n1 * * n2
return n, m, p, e
print 'Entry programme'
test_a()
test_b( 12 , 13 )
test_b( 'www.baidu.com' , 'python' )
sum1 = test_c( 100 , 102 )
print 'sum1 = ' , sum1
sum1, multi, plus, pow1 = test_d( 2 , 10 )
print sum1, multi,plus,pow1
print 'Leave programme'

[root@ceshi ~]# python 1.py

Entry programme

hello the cruel world!

www.baidu.com

12 13

www.baidu.com python

100 102

sum1 =  202

2 10

12 20 -8 1024

Leave programme