What variable name do you use for file descriptors?

Question

A pretty silly trivial question. The canonical example is f = open('filename'), but

• f is not very descriptive. After not looking at code in a while, you can forget whether it means "file" or "function f(x)" or "fourier transform results" or something else. EIBTI.
• In Python, file is already taken by a function.

What else do you use?

Answer 1

 dataFile
 settingsFile
 resultsFile
 .... etc

Answer 2

generally I'll use "fp" for a short-lifetime file pointer.

for a longer-lived descriptor, I'll be more descriptive. "fpDebugLog", for example.

Answer 3

You can append it to the beginning, Hungarian-like "file_fft".

However, I would try to close file descriptors as soon as possible, and I recommend using the with statement like this so you don't have to worry about closing it, and it makes it easier to not lose track of it.

with open("x.txt") as f:
    data = f.read()
    do something with data

Answer 4

I'm happy to use f (for either a function OR a file;-) if that identifier's scope is constrained to a pretty small compass (such as with open('zap') as f: would normally portend, say). In general, identifiers with large lexical scopes should be longer and more explicit, ones with lexically small/short scopes/lifespans can be shorter and less explicit, and this applies to open file object just about as much as to any other kind of object!-)

Answer 5

I rather use one of: f, fp, fd.

Sometimes inf / outf for input and output file.

Answer 6

Generally if the scope of a file object is only a few lines, f is perfectly readable - the variable name for the filename in the open call is probably descriptive enough. otherwise something_file is probably a good idea.