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')

Answer 1

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.

Answer 2

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

Answer 3

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.