deleting file if it exists; python

Question

I want to create a file; if it already exists I want to delete it and create it anew. I tried doing it like this but it throws a Win32 error. What am I doing wrong?

try:
    with open(os.path.expanduser('~') + '\Desktop\input.txt'):
        os.remove(os.path.expanduser('~') + '\Desktop\input.txt')
        f1 = open(os.path.expanduser('~') + '\Desktop\input.txt', 'a')
except IOError:
    f1 = open(os.path.expanduser('~') + '\Desktop\input.txt', 'a')

Does this answer your question? Most pythonic way to delete a file which may not exist — Ricardo Decal
– Ricardo Decal, Commented Nov 22, 2021 at 1:11

Aya · Accepted Answer · 2013-04-23 11:33:50Z

41

You're trying to delete an open file, and the docs for os.remove() state...

On Windows, attempting to remove a file that is in use causes an exception to be raised

You could change the code to...

filename = os.path.expanduser('~') + '\Desktop\input.txt'
try:
    os.remove(filename)
except OSError:
    pass
f1 = open(filename, 'a')

...or you can replace all that with...

f1 = open(os.path.expanduser('~') + '\Desktop\input.txt', 'w')

...which will truncate the file to zero length before opening.

edited Apr 23, 2013 at 11:33

answered Apr 23, 2013 at 11:25

Aya

42.5k6 gold badges60 silver badges56 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

jamylak Over a year ago

This is a potential race condition, check os.path.exists before removing it that is

jamylak Over a year ago

Another program may be operating on the file and deletes it just after os.path.exists evaluates to True.

jamylak Over a year ago

Oh yup it's fine now, I realized just after I wrote mine you could use 'w' but I had that before

mechatroner Over a year ago

safer way to do this: stackoverflow.com/questions/10840533/…

jamylak · Accepted Answer · 2013-04-23 11:24:37Z

3

You are trying to remove the file while it is open, you don't even need that with there to delete it:

path = os.path.join(os.path.expanduser('~'), 'Desktop/input.txt')
with open(path, 'w'): as f:
    # do stuff

Deletes if it exists

answered Apr 23, 2013 at 11:24

jamylak

134k30 gold badges238 silver badges240 bronze badges

Comments

ndpu · Accepted Answer · 2013-04-23 11:22:56Z

2

You can use open with mode parameter = 'w'. If mode is omitted, it defaults to 'r'.

with open(os.path.expanduser('~') + '\Desktop\input.txt', 'w')

w Truncate file to zero length or create text file for writing. The stream is positioned at the beginning of the file.

answered Apr 23, 2013 at 11:22

ndpu

22.6k6 gold badges61 silver badges72 bronze badges

2 Comments

jamylak Over a year ago

@Yui I don't understand you said you want to delete it if it exists... Please update your question with no strings attached

Yui Over a year ago

Yes I want to delete it if it already exists before i start the script. After creating it anew I have multiple strings that get attached to the new file

RichieHindle · Accepted Answer · 2013-04-23 11:22:26Z

1

Windows won't let you delete an open file (unless it's opened with unusual sharing options). You'll need to close it before deleting it:

try:
    with open(os.path.expanduser('~') + '\Desktop\input.txt') as existing_file:
        existing_file.close()
        os.remove(os.path.expanduser('~') + '\Desktop\input.txt')

answered Apr 23, 2013 at 11:22

RichieHindle

283k49 gold badges367 silver badges408 bronze badges

Comments

Maryam Arshi · Accepted Answer · 2013-04-23 12:10:57Z

1

Try this:

 from os import path, 
    PATH = os.path.expanduser('~') + '\Desktop\input.txt'
    if path.isfile(PATH):
       try:
          os.remove(os.path.expanduser('~') + '\Desktop\input.txt')
       except OSError:
          pass

edited :

from os import path, 
        PATH = os.path.expanduser('~') + '\Desktop\input.txt'
        try:
            os.remove(os.path.expanduser('~') + '\Desktop\input.txt')
        except OSError:
            pass

edited Apr 23, 2013 at 12:10

answered Apr 23, 2013 at 11:26

Maryam Arshi

2,0342 gold badges20 silver badges34 bronze badges

4 Comments

jamylak Over a year ago

potential race condition here as well

jamylak Over a year ago

There's no race condition now but the path.isfile(PATH) has become effectively redundant

Maryam Arshi Over a year ago

Thank you, I thought it would make the solution safer.In this case I think my solution will be exactly same as Aya.

jamylak Over a year ago

It doesn't make it any safer as Aya's. Your solution just does two checks instead of one, where the first one doesn't help the security at all, only the second does

Collectives™ on Stack Overflow

deleting file if it exists; python

5 Answers 5

4 Comments

Comments

2 Comments

Comments

4 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

4 Comments

Comments

2 Comments

Comments

4 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related