How can I create a tmp file in Python?
I have this function that references the path of a file:
some_obj.file_name(FILE_PATH)
where FILE_PATH is a string of the path of a file, i.e. H:/path/FILE_NAME.ext
I want to create a file FILE_NAME.ext inside my python script with the content of a string:
some_string = 'this is some content'
How to go about this? The Python script will be placed inside a Linux box.
Solution 1:
I think you're looking for this: http://docs.python.org/library/tempfile.html
import tempfile
with tempfile.NamedTemporaryFile() as tmp:
print(tmp.name)
tmp.write(...)
But:
Whether the name can be used to open the file a second time, while the named temporary file is still open, varies across platforms (it can be so used on Unix; it cannot on Windows NT or later).
If that is a concern for you:
import os, tempfile
tmp = tempfile.NamedTemporaryFile(delete=False)
try:
print(tmp.name)
tmp.write(...)
finally:
tmp.close()
os.unlink(tmp.name)
Solution 2:
There is a tempfile
module for python, but a simple file creation also does the trick:
new_file = open("path/to/FILE_NAME.ext", "w")
Now you can write to it using the write
method:
new_file.write('this is some content')
With the tempfile
module this might look like this:
import tempfile
new_file, filename = tempfile.mkstemp()
print(filename)
os.write(new_file, "this is some content")
os.close(new_file)
With mkstemp
you are responsible for deleting the file after you are done with it. With other arguments, you can influence the directory and name of the file.
UPDATE
As rightfully pointed out by Emmet Speer, there are security considerations when using mkstemp
, as the client code is responsible for closing/cleaning up the created file. A better way to handle it is the following snippet (as taken from the link):
import os
import tempfile
fd, path = tempfile.mkstemp()
try:
with os.fdopen(fd, 'w') as tmp:
# do stuff with temp file
tmp.write('stuff')
finally:
os.remove(path)
The os.fdopen
wraps the file descriptor in a Python file object, that closes automatically when the with
exits. The call to os.remove
deletes the file when no longer needed.