python 用类方法和静态方法实现是追加写文件内容，和读指定行号的内容

用类方法和静态方法实现：一个是追加写文件一行内容，一个是读指定行号的内容

 

#coding=utf-8

 

class handle_file(object):

    def __init__(self,file_path):

        self.file_path=file_path

 

 

 

    @classmethod

    def write_file(cls,file_path,content):

        with open(file_path,'a') as fp:

            fp.write(content)

   

    def readContent(self):

        with open(self.file_path) as fp:

            return fp.read()

 

    @staticmethod

    def read_file(file_path,line_nbr):

        with open(file_path,'r') as fp:

            strList=fp.readlines()

            print strList

            if strList[line_nbr-1]=='\n':

                print 'error'

            else:

                return strList[line_nbr-1]

 

 

 

s="1ssdfsdf\n2dfsdfs\n3sdfsdf\n"

 

operation=handle_file('d:\\0410.txt')

handle_file.write_file('d:\\0410.txt',s)

print handle_file.read_file('d:\\0410.txt',2)

print operation.readContent()

 

c:\Python27\Scripts>python task_test.py

['1ssdfsdf\n', '2dfsdfs\n', '3sdfsdf\n']

2dfsdfs

 

1ssdfsdf

2dfsdfs

3sdfsdf