How to delete only the content of file in python

I have a temporary file with some content and a python script generating some output to this file. I want this to repeat N times, so I need to reuse that file (actually array of files). I'm deleting the whole content, so the temp file will be empty in the next cycle. For deleting content I use this code:

def deleteContent(pfile):

    pfile.seek(0)
    pfile.truncate()
    pfile.seek(0) # I believe this seek is redundant

    return pfile

tempFile=deleteContent(tempFile)

My question is: Is there any other (better, shorter or safer) way to delete the whole content without actually deleting the temp file from disk?

Something like tempFile.truncateAll()?

How to delete only the content of file in python

There are several ways of setting the logical size of a file to 0, depending how you access that file:

To empty an open file:

def deleteContent(pfile):
    pfile.seek(0)
    pfile.truncate()

To empty an open file whose file descriptor is known:

def deleteContent(fd):
    os.ftruncate(fd, 0)
    os.lseek(fd, 0, os.SEEK_SET)

To empty a closed file (whose name is known)

def deleteContent(fName):
    with open(fName, "w"):
        pass

I have a temporary file with some content [...] I need to reuse that file

That being said, in the general case it is probably not efficient nor desirable to reuse a temporary file. Unless you have very specific needs, you should think about using tempfile.TemporaryFile and a context manager to almost transparently create/use/delete your temporary files:

import tempfile

with tempfile.TemporaryFile() as temp:
     # do whatever you want with `temp`

# <- `tempfile` guarantees the file being both closed *and* deleted
#     on the exit of the context manager