How can I safely create a nested directory in Python?

Michael Zippo

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What is the most elegant way to check if the directory a file is going to be written to exists, and if not, create the directory using Python? Here is what I tried:

import os

file_path = "/my/directory/filename.txt"
directory = os.path.dirname(file_path)

try:
    os.stat(directory)
except:
    os.mkdir(directory)

f = file(filename)

Somehow, I missed os.path.exists (thanks kanja, Blair, and Douglas). This is what I have now:

def ensure_dir(file_path):
    directory = os.path.dirname(file_path)
    if not os.path.exists(directory):
        os.makedirs(directory)

Is there a flag for "open", that makes this happen automatically?

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dirname

os.path.dirname(__file__) returns empty

2 answers

I want to get the path of the current directory under which a .py file is executed.

For example a simple file D: est.py with code:

import os

print os.getcwd()
print os.path.basename(__file__)
print os.path.abspath(__file__)
print os.path.dirname(__file__)

It is weird that the output is:

D:
test.py
D:	est.py
EMPTY

I am expecting the same results from the getcwd() and path.dirname().

Given os.path.abspath = os.path.dirname + os.path.basename, why

os.path.dirname(__file__)

returns empty?

174

Answer #1

Because os.path.abspath = os.path.dirname + os.path.basename does not hold. we rather have

os.path.dirname(filename) + os.path.basename(filename) == filename

Both dirname() and basename() only split the passed filename into components without taking into account the current directory. If you want to also consider the current directory, you have to do so explicitly.

To get the dirname of the absolute path, use

os.path.dirname(os.path.abspath(__file__))

dirname

What is the difference between os.path.basename() and os.path.dirname()?

2 answers

What is the difference between os.path.basename() and os.path.dirname()?

I already searched for answers and read some links, but didn"t understand. Can anyone give a simple explanation?

158

Answer #1

Both functions use the os.path.split(path) function to split the pathname path into a pair; (head, tail).

The os.path.dirname(path) function returns the head of the path.

E.g.: The dirname of "/foo/bar/item" is "/foo/bar".

The os.path.basename(path) function returns the tail of the path.

E.g.: The basename of "/foo/bar/item" returns "item"

From: http://docs.python.org/3/library/os.path.html#os.path.basename

We hope this article has helped you to resolve the problem. Apart from How can I safely create a nested directory in Python?, check other code Python module-related topics.

Want to excel in Python? See our review of the best Python online courses 2023. If you are interested in Data Science, check also how to learn programming in R.

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Boris Innsbruck

California | 2023-01-27

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Dmitry Porretti

Texas | 2023-01-27

Maybe there are another answers? What How can I safely create a nested directory in Python? exactly means?. Checked yesterday, it works!

Cornwall Robinson

Boston | 2023-01-27

I was preparing for my coding interview, thanks for clarifying this - How can I safely create a nested directory in Python? in Python is not the simplest one. I just hope that will not emerge anymore