Invoke python script through make command

Question

I have a tool with 5 python scripts say A.py, B.py, C.py, D.py and E.py. I have to run this program in Linux. A.py is the one program I run which imports other files and uses them. For running A.py, I use the command

$ python A.py

Until now the input and output paths are hardcoded in A.py. Now I am supposed to write a makefile with all the file structure and dependencies. This makefile should also include the command for executing python scrip A.py. The required input and output paths has to be understood when make makefile command is invoked and the tool should start running. How to do this?

EDITED :

The makefile should be something like this holding all these details.

INPUT_PATH = list of all input paths
FILES = list of .c files located in the above specified paths
OUTPUT_PATH = output path where generated file has to be stored
command to execute python scrip:
   A.py inputpath+filename outputpath

so whenever there a new input .c files, they will be added to the list in makefile. Any sample makefile of this kind that you could suggest?

Answer 1

In python you get the commandline parameters from sys.argv so instead of

#!/usr/bin/env python
base_dir = /hard/coded/path

you do:

#!/usr/bin/env python
import sys
base_dir = sys.argv[1]

(putting in checks might be appropriate). If you explicitly start the program with python, you can leave out the first line, but it won't hurt to be there in case you make A.py executable, you will need it.

In your makefile you now can specify:

default:
        python A.py /hard/coded/path

(make sure you have a Tabbefore python, not 8 spaces.

And then you can run make (no need to do make makefile unless you have a Makefile or with Gnu make a GNUmakefile in the same directory)

Answer 2

Here I found the most elegant practice with Makefile

Steps:

• Define a variable here I use BROWSER_PYSCRIPT
• Input the python (or any language) script that you want to invoke.
• Export the script with export
• Execute the script with python -c "$$BROWSER_PYSCRIPT"

Running makefile:

Simple use:

• make BROWSER

    define BROWSER_PYSCRIPT
    import sys, os
    print ('sys.argv[0] =', sys.argv[0])
    pathname = os.path.dirname(sys.argv[0])
    print ('path =', pathname)
    print ('full path =', os.path.abspath(pathname))
    endef
    export BROWSER_PYSCRIPT
    BROWSER:
           python -c "$$BROWSER_PYSCRIPT"

RESULTS:

    -> make BROWSER                                                                                                    [Thu Jun 11 23:13:45 2020]
python -c "$BROWSER_PYSCRIPT"
sys.argv[0] = -c
path =
full path = /Users/myPC/Desktop

Answer 3

I strongly suggest, you read a basic Makefile tutorial.

What you basically want, is putting your paths in macros, which in those instances work similar to variables.

for instance DIR=/your/path.

Be aware, that directives look like this:

directive:
        command

if your directive is named default or all it'll get executed without explicitly calling the directive from command line. So you don't have to invoke with make directive, just make.

Now, the space in front of the command, must be a tab character. I also advice naming your makefile Makefile (capital 'M'), so you can invoke it, just by typing make.

now, your script must be able to receive a command line argument (in this case the directories), and you'd invoke something like:

        python A.py $(DIR)

With DIR being your macro with the proper directory name.

Also, I advice reading the relevant bits of the GNU Make manual

There is of course quite a bit more to Makefiles than what is described in this scope. Since makefiles are quite an integral part of developing on Linux, I strongly advice getting to grips with the basics, at least!