In Python, how can I open a file and read it on one line, and still be able to close the file afterwards?

Question

While working through this exercise I ran into a problem.

from sys import argv
from os.path import exists

script, from_file, to_file = argv
print \"Copying from         


        

Answer 1

The preferred way to work with resources in python is to use context managers:

 with open(infile) as fp:
    indata = fp.read()

The with statement takes care of closing the resource and cleaning up.

You could write that on one line if you want:

 with open(infile) as fp: indata = fp.read()

however, this is considered bad style in python.

You can also open multiple files in a with block:

with open(input, 'r') as infile, open(output, 'w') as outfile:
    # use infile, outfile

Funny enough, I asked exactly the same question back when I started learning python.