python读取大文件并逐行写入另外一个文件

creazy.txt文件有4G，逐行读取其内容并写入monday.txt文件里。
 
  
 
  
def creazyRead():
    '''
    with open("e:creazy.txt","r") as cr:
        for line in cr:
            print line
    '''
    ms = open("e:creazy.txt")
    for line in ms:
        with open("e:monday.txt","a") as mon:
            mon.write(line)
 
  
另一种方法使用readlines实现：
 
  
def creazyRead():
    ms = open("e:creazy.txt")
    for line in ms.readlines():
        with open("e:monday.txt","a") as mon:
            mon.write(line)