Write file to a directory that doesn't exist

Question

How do I using with open() as f: ... to write the file in a directory that doesn't exist.

For example:

with open('/Users/bill/output/output-text.txt', 'w') as file_to_write:
    file_to_write.write("{}\n".format(result))

Let's say the /Users/bill/output/ directory doesn't exist. If the directory doesn't exist just create the directory and write the file there.

Answer 1

You need to first create the directory.

The mkdir -p implementation from this answer will do just what you want. mkdir -p will create any parent directories as required, and silently do nothing if it already exists.

Here I've implemented a safe_open_w() method which calls mkdir_p on the directory part of the path, before opening the file for writing:

import os, os.path
import errno

# Taken from https://stackoverflow.com/a/600612/119527
def mkdir_p(path):
    try:
        os.makedirs(path)
    except OSError as exc: # Python >2.5
        if exc.errno == errno.EEXIST and os.path.isdir(path):
            pass
        else: raise

def safe_open_w(path):
    ''' Open "path" for writing, creating any parent directories as needed.
    '''
    mkdir_p(os.path.dirname(path))
    return open(path, 'w')

with safe_open_w('/Users/bill/output/output-text.txt') as f:
    f.write(...)

Updated for Python 3:

import os, os.path

def safe_open_w(path):
    ''' Open "path" for writing, creating any parent directories as needed.
    '''
    os.makedirs(os.path.dirname(path), exist_ok=True)
    return open(path, 'w')

with safe_open_w('/Users/bill/output/output-text.txt') as f:
    f.write(...)

Answer 2

For Python 3 can use with pathlib.Path :

from pathlib import Path

p = Path('Users'/'bill'/'output')
p.mkdir(exist_ok=True)
with (p / 'output-text.txt').open('w') as opened_file:
    opened_file.write(...)

Answer 3

Make liberal use of the os module:

import os

if not os.path.isdir('/Users/bill/output'):
    os.mkdir('/Users/bill/output')

with open('/Users/bill/output/output-text.txt', 'w') as file_to_write:
    file_to_write.write("{}\n".format(result))

Answer 4

The answer given by Yakir Tsuberi is great but I would like to add that you need the parameter parents=True for nested folders as explained here . Thus, the code would look as follows:

from pathlib import Path

p = Path('Users/bill/output')
p.mkdir(parents=True, exist_ok=True)
with (p / 'output-text.txt').open('w') as opened_file:
    opened_file.write(...)

Answer 5

You can just create the path you want to create the file using os.makedirs :

import os
import errno

def make_dir(path):
    try:
        os.makedirs(path, exist_ok=True)  # Python>3.2
    except TypeError:
        try:
            os.makedirs(path)
        except OSError as exc: # Python >2.5
            if exc.errno == errno.EEXIST and os.path.isdir(path):
                pass
            else: raise

Source: this SO solution