Question

This is a bit strange. My program isn’t able to write the output to a file. Its even not showing any error. I simultaneously used standard output and found that its showing..

This is my code: (Python 2.7)

#!/usr/bin/env python


import re

def isRecycled(n,m):
    n = str(n)
    m = str(m)

    try:
        ...........
        ...........
        My Code.

    except ValueError:
        return False

ip = open("C-small-attempt0.in", "r")
op = open("output.txt", "a")
for num, eachLine in enumerate( ip.readlines()[1:] ):
    ......
    ......
    My code

    ## This is WORKING
    print "Case #%d: %d" %(num+1, count)

    ## This is NOT Working
    op.write("Case #%d: %d" %(num+1, count))

Can anyone tell me why this is not writing to the file.

I tried to use "w+", "w" modes and also writelines() method but they didn’t work.

Edited

However, it worked when I closed the file using op.close()

1. Why this is happening? (I didn’t encounter it previously)
2. Does python immediately write to the file as soon as it finds op.write()?

Answer 1

You need to close the file for it to write to disk. Add op.close() to the end of your code.