How To Execute A Python Script In A Different Directory?

Solved see my answer below for anyone who might find this helpful. I have two scripts a.py and b.py. In my current directory 'C:\Users\MyName\Desktop\MAIN', I run > python a.py.

Solution 1:

The easiest answer is probably to change your working directory, then call the second .py file from where it is:

python a.py && cd testA && python ../b.py

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Of course you might find it even easier to write a script that does it all for you, like so:

Save this as runTests.sh in the same directory as a.py is:

#!/bin/sh
python a.py
cd testA
python ../b.py

Make it executable:

chmod +x ./runTests.sh

Then you can simply enter your directory and run it:

./runTests.sh

Solution 2:

I managed to get b.py executing and producing the testB folder where I need it to, while remaining in the MAIN folder. For anyone who might wonder, at the beginning of my b.py script I would simply use mydir = os.getcwd() which normally is wherever b.py is.

To keep b.py in MAIN while making it work on files in other directories, I wrote this:

mydir = os.getcwd() # would be the MAIN folder
mydir_tmp = mydir + "//testA" # add the testA folder name
mydir_new = os.chdir(mydir_tmp) # change the current working directory
mydir = os.getcwd() # set the main directory again, now it calls testA

Running the bash script now works!

Solution 3:

Your b.py script could take the name of the directory as a parameter. Access the first parameter passed to b.py with:

import sys
dirname = sys.argv[1]

Then iterate over the files in the named directory with:

import os
for filename in os.listdir(dirname):
    process(filename)

Also see glob.glob and os.walk for more options processing files.

Solution 4:

despite there are already answers i still wrote a script out of fun and it still could be of help in some respects. I wrote it for python3, so it is necessary to tweak some minor things to execute it on v2.x (e.g. the prints).

Anyways... the code creates a new folder relative to the location of a.py, creates and fills script b.py with code, executes b and displays b's results and errors.

The resulting path-structure is: testFolder |-testA | |-a.py |-testB | |-b.py

The code is:

import os, sys, subprocess

def getRelativePathOfNewFolder(folderName):
    return "../" + folderName + "/"

def getAbsolutePathOfNewFolder(folderName):
    # create new folder with absolute path:
    #   get path of current script:
    tmpVar = sys.argv[0]
    #   separate path from last slash and file name:
    tmpVar = tmpVar[:sys.argv[0].rfind("/")]
    #   again to go one folder up in the path, but this time let the slash be:
    tmpVar = tmpVar[:tmpVar.rfind("/")+1]
    #   append name of the folder to be created:
    tmpVar += folderName + "/"

    # for the crazy ones out there, you could also write this like this:
    # tmpVar = sys.argv[0][:sys.argv[0].rfind("/", 0, 
    sys.argv[0].rfind("/")-1)+1] + folderName + "/"
    return tmpVar

if __name__ == "__main__":
    # do stuff here:
    # ...
    # create new folder:
    bDir = getAbsolutePathOfNewFolder("testB")
    os.makedirs(bDir, exist_ok=True) # makedirs can create new nested dirs at once. e.g: "./new1/new2/andSoOn"
    # fill new folder with stuff here:
    # ...
    # create new python file in location bDir with code in it:
    bFilePath = bDir + "b.py"
    with open(bFilePath, "a") as toFill:
        toFill.write("if __name__ == '__main__':")
        toFill.write("\n")
        toFill.write("\tprint('b.py was executed correctly!')")
        toFill.write("\n")
        toFill.write("\t#do other stuff")

    # execute newly created python file
    args = (
        "python",
        bFilePath
    )
    popen = subprocess.Popen(args, stdout=subprocess.PIPE)
    # use next line if the a.py has to wait until the subprocess execution is finished (in this case b.py)
    popen.wait()
    # you can get b.py´s results with this:
    resultOfSubProcess, errorsOfSubProcess = popen.communicate()
    print(str(resultOfSubProcess)) # outputs: b'b.py was executed correctly!\r\n'
    print(str(errorsOfSubProcess)) # outputs: None

    # do other stuff

instead of creating a new code file and filling it with code you of course can simply copy an existing one as shown here: How do I copy a file in python?

Solution 5:

In your batch file, you can set the %PYTHONPATH% variable to the folder with the Python module. This way, you don't have to change directories or use pushd to for network drives. I believe you can also do something like

set "PYTHONPATH=%PYTHONPATH%;c:\the path\to\my folder\which contains my module"

This will append the paths I believe (This will only work if you already have set %PYTHONPATH% in your environment variables).

If you haven't, you can also just do

set "PYTHONPATH=c:\the path\to\my folder\which contains my module"

Then, in the same batch file, you can do something like

python -m mymodule ...