python 学习起步

把学到的都整理到zutil.py里吧

#!/bin/env python
#coding:utf8
# filename: zutil.py
# description: util for myself
# createtime: 2013/10/11
# last modify: 2013/10/11

# open file
import random
import sys
def readfile(filename):
    f = open(filename)
    # f = open(filename, 'a') #append
    # f = open(filename, 'w') # write
    f.write(str(random.randint(0,9)) + '\n')
    f.flush()
    f.close()

def redirectoutput():
    sys.stdout = open("stdout.txt", 'w')

#!/bin/env python
#coding:utf8
# filename: zutil.py
# description: util for myself
# createtime: 2013/10/11
# last modify: 2013/10/11

# open file
import random
import sys
def readfile(filename):
    f = open(filename)
    # f = open(filename, 'a') #append
    # f = open(filename, 'w') # write
    f.write(str(random.randint(0,9)) + '\n')
    f.flush()
    f.close()

def redirectoutput():
    sys.stdout = open("stdout.txt", 'w')

import hashlib
import os
# from a[.py] import something
def getFileMd5(filename):
    myhash = hashlib.md5()
   if not os.path.isfile(filename):
       return
   f = open(filename)
   while True:
      b = f.read(8096)
      if not b:
          break
      myhash.update(b)
   return myhash.hexdigest()
   # return myhash.hexdigest().upper()

# file size
#  os.path.getsize(filename)

经验：
1.  在python里，函数的默认值是在函数定义的时候实例化的，而不是在调用的时候