The os.makedirs function does this. Try the following:
import os
import errno
filename = "/foo/bar/baz.txt"
if not os.path.exists(os.path.dirname(filename)):
try:
os.makedirs(os.path.dirname(filename))
except OSError as exc: # Guard against race condition
if exc.errno != errno.EEXIST:
raise
with open(filename, "w") as f:
f.write("FOOBAR")
The reason to add the try-except block is to handle the case when the directory was created between the os.path.exists and the os.makedirs calls, so that to protect us from race conditions.
In Python 3.2+, there is a more elegant way that avoids the race condition above:
import os
filename = "/foo/bar/baz.txt"
os.makedirs(os.path.dirname(filename), exist_ok=True)
with open(filename, "w") as f:
f.write("FOOBAR")