Does with-statement function close files?

Question

In this simple file IO operation, is x.txt closed at the end of f.read? Also, how would I check to see if that file is still open or not?

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

Answer 1

The file object referenced by f will be closed when control leaves the with-statement's code block. In fact, that is why you use a with-statement to open a file in the first place. Other than automatically closing the file when done, the construct serves no purpose.

You can test this for yourself by printing the f.closed flag:

with open("x.txt") as f:
    data = f.read()
    ## Still inside with block ##
    print f.closed  # Output: False

## Outside of with block ##
print f.closed  # Output: True

Answer 2

Documentation:

It is good practice to use the with keyword when dealing with file objects. This has the advantage that the file is properly closed after its suite finishes, even if an exception is raised on the way. It is also much shorter than writing equivalent try-finally blocks: