Reputation:
I am writing a data processing code, in which I create a new file, write processed data in to this file and close. But the file has to be closed in read-only mode, so that it would not be accidentally modified. Can this be done in Python?
Upvotes: 25
Views: 46734
Reputation: 1201
Using pathlib.Path
, for modern python3, use path.chmod(mode: int)
The octal mode could be specified like 0o444
(read only). See this for more chmod mode options.
Note, if it is to apply to the symlink itself, see path.lchmod
.
For path.chmod
, after 3.10, there's now a follow_symlinks = True
parameter as well.
On windows, this may not be sufficient for anything but twiddling the read-only flag. See other SO posts [1].
Upvotes: 4
Reputation: 136
This solution preserves previous permission of the file, acting like command chmod -w FILE
import os
import stat
filename = "path/to/file"
mode = os.stat(filename).st_mode
ro_mask = 0o777 ^ (stat.S_IWRITE | stat.S_IWGRP | stat.S_IWOTH)
os.chmod(filename, mode & ro_mask)
Upvotes: 6
Reputation: 1
For Windows OS maybe to try something like this:
import os
filename = open("file_name.txt", "w")
filename.write("my text")
filename.close()
os.system("attrib +r file_name.txt")
Upvotes: -2
Reputation: 9085
For this you use os.chmod
import os
from stat import S_IREAD, S_IRGRP, S_IROTH
filename = "path/to/file"
os.chmod(filename, S_IREAD|S_IRGRP|S_IROTH)
Note that this assumes you have appropriate permissions, and that you want more than just the owner to be able to read the file. Remove S_IROTH
and S_IRGRP
as appropriate if that's not the case.
UPDATE
If you need to make the file writable again, simply call os.chmod
as so:
from stat import S_IWUSR # Need to add this import to the ones above
os.chmod(filename, S_IWUSR|S_IREAD) # This makes the file read/write for the owner
Simply call this before you open the file for writing, then call the first form to make it read-only again after you're done.
Upvotes: 39
Reputation: 700
I guess you could use os module after writing on your file to change the file permissions like this:
import os
filename=open("file_name","w")
filename.write("my text")
filename.close()
os.system("chmod 444 file_name")
Upvotes: -3