Open document with default OS application in Python, both in Windows and Mac OS
Just for completeness (it wasn't in the question), xdg-open will do the same on Linux.
I prefer:
os.startfile(path, 'open')
Note that this module supports filenames that have spaces in their folders and files e.g.
A:\abc\folder with spaces\file with-spaces.txt
(python docs) 'open' does not have to be added (it is the default). The docs specifically mention that this is like double-clicking on a file's icon in Windows Explorer.
This solution is windows only.
Use the subprocess
module available on Python 2.4+, not os.system()
, so you don't have to deal with shell escaping.
import subprocess, os, platform
if platform.system() == 'Darwin': # macOS
subprocess.call(('open', filepath))
elif platform.system() == 'Windows': # Windows
os.startfile(filepath)
else: # linux variants
subprocess.call(('xdg-open', filepath))
The double parentheses are because subprocess.call()
wants a sequence as its first argument, so we're using a tuple here. On Linux systems with Gnome there is also a gnome-open
command that does the same thing, but xdg-open
is the Free Desktop Foundation standard and works across Linux desktop environments.
open
and start
are command-interpreter things for Mac OS/X and Windows respectively, to do this.
To call them from Python, you can either use subprocess
module or os.system()
.
Here are considerations on which package to use:
You can call them via
os.system
, which works, but...Escaping:
os.system
only works with filenames that don't have any spaces or other shell metacharacters in the pathname (e.g.A:\abc\def\a.txt
), or else these need to be escaped. There isshlex.quote
for Unix-like systems, but nothing really standard for Windows. Maybe see also python, windows : parsing command lines with shlex- MacOS/X:
os.system("open " + shlex.quote(filename))
- Windows:
os.system("start " + filename)
where properly speakingfilename
should be escaped, too.
- MacOS/X:
You can also call them via
subprocess
module, but...For Python 2.7 and newer, simply use
subprocess.check_call(['open', filename])
In Python 3.5+ you can equivalently use the slightly more complex but also somewhat more versatile
subprocess.run(['open', filename], check=True)
If you need to be compatible all the way back to Python 2.4, you can use
subprocess.call()
and implement your own error checking:try: retcode = subprocess.call("open " + filename, shell=True) if retcode < 0: print >>sys.stderr, "Child was terminated by signal", -retcode else: print >>sys.stderr, "Child returned", retcode except OSError, e: print >>sys.stderr, "Execution failed:", e
Now, what are the advantages of using
subprocess
?- Security: In theory, this is more secure, but in fact we're needing to execute a command line one way or the other; in either environment, we need the environment and services to interpret, get paths, and so forth. In neither case are we executing arbitrary text, so it doesn't have an inherent "but you can type
'filename ; rm -rf /'
" problem, and if the file name can be corrupted, usingsubprocess.call
gives us little additional protection. - Error handling: It doesn't actually give us any more error detection, we're still depending on the
retcode
in either case; but the behavior to explicitly raise an exception in the case of an error will certainly help you notice if there is a failure (though in some scenarios, a traceback might not at all be more helpful than simply ignoring the error). - Spawns a (non-blocking) subprocess: We don't need to wait for the child process, since we're by problem statement starting a separate process.
To the objection "But
subprocess
is preferred." However,os.system()
is not deprecated, and it's in some sense the simplest tool for this particular job. Conclusion: usingos.system()
is therefore also a correct answer.A marked disadvantage is that the Windows
start
command requires you to pass inshell=True
which negates most of the benefits of usingsubprocess
.- Security: In theory, this is more secure, but in fact we're needing to execute a command line one way or the other; in either environment, we need the environment and services to interpret, get paths, and so forth. In neither case are we executing arbitrary text, so it doesn't have an inherent "but you can type