CODEWITHSUNDEEP
pythonfileif-statement
Stefan
Stefan

Reputation: 1533

Use another file A if file B does not exist

I think it is a simple task. I tried a lot of things with no success.

I want to use a file A on a network directory and when I'm offline I want to use file B on my ssd.

file_PATH = "y:/file_A.txt"

if os.path.isfile(file_PATH):
    file_to_use = "y:/file_A.txt"
else:
    file_to_use = "d:/file_B.txt"

It doesn't work with this piece of code. When I rename file_A for testing, file_B will not be used.

UPDATE

I've found the (very silly) mistake. It was a misspelling of one of the two directories.

Upvotes: 0

Views: 207

Answers (3)

Xeberdee
Xeberdee

Reputation: 2047

import pathlib

file_PATH = pathlib.Path('y:/file_A.txt')

if file_PATH.is_file():
    file_to_use = "y:/file_A.txt"
else:
    file_to_use = "d:/file_B.txt"

EDIT: due to comment about Python 3.4

You can do it with os.path.exists with Python 2:

>>> import os.path
>>> file_path = 'c:/file_false.txt'
>>> os.path.exists(file_path)
False
>>> file_path = 'c:/file_real.txt'
os.path.exists(file_path)
True

So

import os.path
file_PATH = 'y:/file_A.txt'

if os.path.exists(file_path):
    file_to_use = "y:/file_A.txt"
else:
    file_to_use = "d:/file_B.txt"

Upvotes: 1

keul
keul

Reputation: 7819

Use os.path.exists and also think about using os.path.join for building your path.

file_PATH = "y:/file_A.txt"

if os.path.exists(file_PATH):
    file_to_use = "y:/file_A.txt"
else:
    file_to_use = "d:/file_B.txt"

Upvotes: 1

Abhishake Gupta
Abhishake Gupta

Reputation: 3170

I would suggest that you check for the existence of the file.

In python 3.4 : the pathlib module offers an object-oriented approach-:

from pathlib import Path
if Path(r"/path/to/file_A.txt").is_file():
    file_to_use = "y:/file_A.txt"

elif Path(r"/path/to/file_B.txt").is_file():
    file_to_use = "d:/file_B.txt"
else:
    # Do something if both files don't exist

Upvotes: 0

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