I am creating a tmp file by using :
from tempfile import mkstemp
I am trying to write in this file :
tmp_file = mkstemp()
file = open(tmp_file, 'w')
file.write('TEST\n')
Indeed I close the file and do it proper but when I try to cat the tmp file, it stills empty..It looks basic but I don't know why it doesn't work, any explanations ?
mkstemp() returns a tuple with a file descriptor and a path. I think the issue is that you're writing to the wrong path. (You're writing to a path like '(5, "/some/path")'.) Your code should look something like this:
from tempfile import mkstemp
fd, path = mkstemp()
# use a context manager to open the file at that path and close it again
with open(path, 'w') as f:
f.write('TEST\n')
# close the file descriptor
os.close(fd)
The answer by smarx opens the file by specifying path. It is, however, easier to specify fd instead. In that case the context manager closes the file descriptor automatically:
from tempfile import mkstemp
fd, path = mkstemp()
# use a context manager to open (and close) file descriptor fd (which points to path)
with open(fd, 'w') as f:
f.write('TEST\n')
# This causes the file descriptor to be closed automatically
This example opens the Python file descriptor with os.fdopen to write cool stuff, then close it (at the end of the with context block). Other non-Python processes can use the file. And at the end, the file is deleted.
import os
from tempfile import mkstemp
fd, path = mkstemp()
with os.fdopen(fd, 'w') as fp:
fp.write('cool stuff\n')
# Do something else with the file, e.g.
# os.system('cat ' + path)
# Delete the file
os.unlink(path)
