Notes for python (2)

#!/usr/bin/python
#Filename : backup.py
import os
import time

#source list
source = ['/Users/chengflandy/src/python','/Users/chengflandy/src/lsw/frontend/html']

#target directory
target_dir = "/Users/chengflandy/src/backup/"

#today is the name of the sub backup directory
today = target_dir + time.strftime("%Y%m%d")

#current time is the name of the zip archive
now = time.strftime("%H%M%S")

#take a comment fron the user to create the zp
comment = raw_input("Enter a comment for the archive->")

#create the subdirectory if not exists
if not os.path.exists(today):
  os.mkdir(today)
  print "Successfully created directory:",today
  
#the name of the zip file
if len(comment) == 0:
  target = today+os.sep+now+".zip"
else:
  target = today+os.sep+now+"_"+comment.replace(' ','_')+".zip"

#use the zip command to zip
zip_command = "zip -qr %s %s" % (target,' '.join(source))

#run the command
if os.system(zip_command) == 0:
  print "Successful backup to ",target
else:
  print "Back failed"

#!/usr/bin/python
# Filename: objvar.py

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()