Read from file after write, before closing

Question

I'm trying to read from an originally empty file, after a write, before closing it. Is this possible in Python?

with open("outfile1.txt", 'r+') as f:
    f.write("foobar")
    f.flush()
    print("File contents:", f.read())

Flushing with f.flush() doesn't seem to work, as the final f.read() still returns nothing.

Is there any way to read the "foobar" from the file besides re-opening it?

Answer 1

You need to reset the file object's index to the first position, using seek() :

with open("outfile1.txt", 'r+') as f:
    f.write("foobar")
    f.flush()

    # "reset" fd to the beginning of the file
    f.seek(0)
    print("File contents:", f.read())

which will make the file available for reading from it.

Answer 2

File objects keep track of current position in the file. You can get it with f.tell() and set it with f.seek(position) .

To start reading from the beginning again, you have to set the position to the beginning with f.seek(0) .

http://docs.python.org/2/library/stdtypes.html#file.seek

Answer 3

Seek back to the start of the file before reading:

f.seek(0)
print f.read()