10-1 Python 学习笔记：在文本编辑器中新建一个文件，写几句话来总结一下你至此学到的Python 知识，其中每一行都以“In Python you can”打头。将这个文件命名为learning_python.txt，并将其存储到为完成本章练习而编写的程序所在的目录中。编写一个程序，它读取这个文件，并将你所写的内容打印三次：第一次打印时读取整个文件；第二次打印时遍历文件对象；第三次打印时将各行存储在一个列表中，再在with 代码块外打印它们。
新建文件learning_python.txt并添加如下内容
1 In Python you can Handle file 2 In Python you can Automatic operation and maintenance 3 In Python you can make AI
编写python代码
1 filename=‘learning_python.txt‘ 2 with open(filename) as file_object: 3 contents = file_object.read() 4 print(contents.rstrip()) 5 6 print(‘‘) 7 8 with open(filename) as file_object: 9 for line in file_object: 10 print(line.rstrip()) 11 12 print(‘‘) 13 14 with open(filename) as file_object: 15 lines = file_object.readlines() 16for line in lines: 17 print(line.rstrip())
执行结果
1 In Python you can Handle file 2 In Python you can Automatic operation and maintenance 3 In Python you can make AI 4 5 In Python you can Handle file 6 In Python you can Automatic operation and maintenance 7 In Python you can make AI 8 9 In Python you can Handle file 10 In Python you can Automatic operation and maintenance 11 In Python you can make AI
总结：
with 在不需要访问文件后将其关闭
open()返回一个表示文件对象，python将这个文件对象储存到 file_object变量里
read()方法读取文件对象的全部内容，并将其作为一个长长的字符串存储在变量contents中
原文：https://www.cnblogs.com/rainights/p/11757217.html