Python，how do you work

panjianm

　　想写这样的文章有好长时间了，反正最近也没什么任务，所以就来说说Python。
　　Python其实是很简单的一门编程语言了。翻遍所有的书籍，虽然很少，但一看大家都能明白。简简单单的语句就能干出大事情的，我想Python，非你莫属了。
　　这里不想将关于Python的基本语法，感觉太简单，只要学过编程的都会明白这个。什么Hello World啊，大家到网上也会学到很多的。
　　这里提供一个网站
　　http://sebug.net/paper/python/index.html 对于Python 2.x版本有很细的讲解。大概看个一天左右基本都会了。
　　我这个主要讲解Python的小例子和看到的精髓代码，和大家分享一下。
　　第一个：上面网站提供
　　关于Python和window的联合应用问题
　　其实Python是很轻松的调用系统的函数，做一些事情，比如说查看注册表了，打打包什么的，下面的例子就是这样的

import os
import time
# 1. The files and directories to be backed up are specified in a list.
source = [r'D:\home\bin']
# If you are using Windows, use source = [r'C:\Documents', r'D:\Work'] or something like that
# 2. The backup must be stored in a main backup directory
target_dir = 'd:/' # Remember to change this to what you will be using
# 3. The files are backed up into a zip file.
# 4. The current day is the name of the subdirectory in the main directory
today = target_dir + time.strftime('%Y%m%d')
# The current time is the name of the zip archive
now = time.strftime('%H%M%S')
# Create the subdirectory if it isn't already there
if not os.path.exists(today):
os.mkdir(today) # make directory
print 'Successfully created directory', today
# The name of the zip file
target = today + os.sep + now + '.zip'
# 5. We use the zip command (in Unix/Linux) to put the files in a zip archive
zip_command = "zip -qr %s %s" % (target, ' '.join(source))
# Run the backup
if os.system(zip_command) == 0:
print 'Successful backup to', target
else:
print 'Backup FAILED'
　　上面的例子说明：
　　source 为需要打包的目录，target为我想打包的位置和文件名。zip_command就是我要执行的命令，通过os.system来调用系统来执行。os.path来判断文件是否存在。
　　如果看不懂上面的可以看看下面的

import os
import time
# 1. The files and directories to be backed up are specified in a list.
source = [r'D:\home\bin']
# If you are using Windows, use source = [r'C:\Documents', r'D:\Work'] or something like that
# 2. The backup must be stored in a main backup directory
target_dir = 'd:/' # Remember to change this to what you will be using
# 3. The files are backed up into a zip file.
# 4. The name of the zip archive is the current date and time
target = target_dir + time.strftime('%Y%m%d%H%M%S') + '.zip'
# 5. We use the zip command (in Unix/Linux) to put the files in a zip archive
zip_command = "zip -qr %s %s" % (target, ' '.join(source))
# Run the backup
if os.system(zip_command) == 0:
print 'Successful backup to', target
else:
print 'Backup FAILED'

　　这个更简单，更好理解
　　对于一些刚刚接触Python的人来说上面会很难，不知道是干什么的，那么你应该从基础学习一下。查看我给你的网站，进行分析，然后在来看这篇文章，就会发现，有一种上升的感觉哦。
　　对于Python的面向对象，我这里还是会说明一下
　　Python是怎么创建类的

class Person:
pass
p = Person()
print p
　　类的内部函数

class Person:
def sayHi(self,message):
print message
p = Person()
p.sayHi("Hello,how the python work")
 

　　类的方法与普通的函数只有一个特别的区别——它们必须有一个额外的第一个参数名称，但是在调用这个方法的时候你不为这个参数赋值，Python会提供这个值。这个特别的变量指对象本身，按照惯例它的名称是self。
　　类的构造方法的定义

class Person:
def __init__(self, name):
self.name = name
def sayHi(self):
print 'Hello, my name is', self.name
p = Person('chenhailong')
p.sayHi()

　　类的析构函数的定义

class Person:
'''Represents a person.'''
population = 0
def __init__(self, name):
'''Initializes the person's data.'''
self.name = name
print '(Initializing %s)' % self.name
# When this person is created, he/she
# adds to the population
Person.population += 1
def __del__(self):
'''I am dying.'''
print '%s says bye.' % self.name
Person.population -= 1
if Person.population == 0:
print 'I am the last one.'
else:
print 'There are still %d people left.' % Person.population
def sayHi(self):
'''Greeting by the person.
Really, that's all it does.'''
print 'Hi, my name is %s.' % self.name
def howMany(self):
'''Prints the current population.'''
if Person.population == 1:
print 'I am the only person here.'
else:
print 'We have %d persons here.' % Person.population
swaroop = Person('Swaroop')
swaroop.sayHi()
swaroop.howMany()
kalam = Person('Abdul Kalam')
kalam.sayHi()
kalam.howMany()
swaroop.sayHi()
swaroop.howMany()
del swaroop
del kalam

　　类的继承关系好例子

class SchoolMember:
'''Represents any school member.'''
def __init__(self, name, age):
self.name = name
self.age = age
print '(Initialized SchoolMember: %s)' % self.name
def tell(self):
'''Tell my details.'''
print 'Name:"%s" Age:"%s"' % (self.name, self.age),
class Teacher(SchoolMember):
'''Represents a teacher.'''
def __init__(self, name, age, salary):
SchoolMember.__init__(self, name, age)
self.salary = salary
print '(Initialized Teacher: %s)' % self.name
def tell(self):
SchoolMember.tell(self)
print 'Salary: "%d"' % self.salary
class Student(SchoolMember):
'''Represents a student.'''
def __init__(self, name, age, marks):
SchoolMember.__init__(self, name, age)
self.marks = marks
print '(Initialized Student: %s)' % self.name
def tell(self):
SchoolMember.tell(self)
print 'Marks: "%d"' % self.marks
t = Teacher('Mrs. Shrividya', 40, 30000)
s = Student('Swaroop', 22, 75)
print # prints a blank line
members = [t, s]
for member in members:
member.tell() # works for both Teachers and Students