[Python-Dev] file() or open()? (original) (raw)

François Pinard pinard at iro.umontreal.ca
Wed Jul 7 20:30:33 CEST 2004

[Guido van Rossum]

Oops, yes. I didn't write that, and it doesn't convey my feelings about file() vs. open(). Here's a suggestion for better words:

"The file class is new in Python 2.2. It represents the type (class) of objects returned by the built-in open() function. Its constructor is an alias for open(), but for future and backwards compatibility, open() remains preferred."

This is slightly saddening. I perceived the introduction of `file()' as a nice cleanup in Python. I wonder if the quote above states the real reason. Sometimes, we produce rationalisations for what was more of an emotion initially. Here, another message on the same topic says:

Maybe you'll change your mind when open() can return other objects besides files.

Granted that `open()' may be preferred for backwards compatibility, but if it is meant to change or improve in the long run, maybe it should be avoided, precisely for future compatibility.

Currently, I use file()' when the meaning of my code is to create a file object to be operated upon, but to otherwise let Python manage it. Yet, I still use open()' when the meaning of my code is opening a file, usually implying that I will also explicitly close it. If open()' could return objects of various types, and my goal is really to get a file object, may I presume that file()' imposes itself as preferred?

-- François Pinard http://www.iro.umontreal.ca/~pinard

More information about the Python-Dev mailing list