CODEWITHSUNDEEP
pythonfilefile-io
Keef Baker
Keef Baker

Reputation: 641

file not being released in python

I have a simple block of code that opens a file then after running through a for loop it closes the file.

However it doesn't seem to release the file because the following line underneath the loop and close

print os.stat('/root/message').st_size

shows as 0. If I do an ls -l it shows the filesize and I can cat the file out and it has the correct contents.

Here's the code block.

#!/usr/bin/python
import os
objects = { 'dave' : 'builder' , 'fred' : 'cobbler' , 'frank' : 'shoplifter' }
log = open('/root/jam' , 'w')
for bloke in objects:
        log.write("%s is a %s \n" % (bloke, objects[bloke])) 
log.close
print os.stat('/root/jam').st_size

What am I doing wrong here?

Upvotes: 1

Views: 70

Answers (2)

Abdul Majeed
Abdul Majeed

Reputation: 2781

Don't know what is the issue with write mode but it can be done using 'r+'.

import os
objects = { 'dave' : 'builder' , 'fred' : 'cobbler' , 'frank' : 'shoplifter' }
log = open('jam.txt', 'r+')
for bloke in objects:
    log.write("%s is a %s \n" % (bloke, objects[bloke])) 
log.close()
print os.stat('jam.txt').st_size

Other modes can be seen on http://www.tutorialspoint.com/python/python_files_io.htm

Upvotes: 0

Martijn Pieters
Martijn Pieters

Reputation: 1121316

You forgot to call the file.close method; add () to not just reference the method but actually invoke it:

log.close()

Python otherwise would auto-close the file as soon as your script ends, which is why the ls -l and cat commands show you a size and the file contents.

You could also use the file object as a context manager, using the with statement; as soon as the with block ends the file will be closed for you:

import os

objects = { 'dave' : 'builder' , 'fred' : 'cobbler' , 'frank' : 'shoplifter' }

with open('/root/jam' , 'w') as log:
    for bloke in objects:
        log.write("%s is a %s \n" % (bloke, objects[bloke]))

# with block ends, file is closed for you

print os.stat('/root/jam').st_size

Upvotes: 6

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