Python初试云雨情

fd = file(filename, "r",encoding='utf-8')  
上句运行出现错误：NameError: name 'file' is not defined

解决办法：file()改为open()，python 3.0 不再支持file

file

2to3 fixer ☐ six support ☐

In Python 2 there is a file type builtin. This is replaced with various file types in Python 3. You commonly see code in Python 2 that uses file(pathname)which will fail in Python 3.

Replace this usage with open(pathname).If you need to test for types you can in Python 3 check for io.IOBase instead of file.

IOBase是一个上下文管理器，所以也支持with语句。在这个例子中，文件在with语句块执行完成后被关闭，即使错误发生也会关闭文件。

    with open('spam.txt', 'w') as file:
         file.write('spam and eggs')