make file ideas:

Define paths for virtual environments

PY27_ENV = py27env
PY3_ENV = py3env

Define the Python versions

PY27 = python2.7
PY3 = python3

Define paths for scripts

MAIN_SCRIPT = main.py
EXAMPLE_SCRIPT = example.py

Rule to create the Python 2.7 virtual environment

$(PY27_ENV)/bin/activate: requirements-py27.txt
virtualenv -p $(PY27) $(PY27_ENV)
$(PY27_ENV)/bin/pip install -r requirements-py27.txt

Rule to create the Python 3.x virtual environment

$(PY3_ENV)/bin/activate: requirements-py3.txt
$(PY3) -m venv $(PY3_ENV)
$(PY3_ENV)/bin/pip install -r requirements-py3.txt

Rule to run the Python 2.7 script

run_py27: $(PY27_ENV)/bin/activate
$(PY27_ENV)/bin/python $(MAIN_SCRIPT)

Rule to run the Python 3.x script

run_py3: $(PY3_ENV)/bin/activate
$(PY3_ENV)/bin/python $(EXAMPLE_SCRIPT) 10

Rule to clean up the virtual environments

clean:
rm -rf $(PY27_ENV) $(PY3_ENV)

Rule to run everything

all: run_py27 run_py3

#Example of python2.7 script

main.py (Python 2.7 script)

import subprocess
import os

def run_python3_script(venv_path, script_path, *args):
python3_interpreter = os.path.join(venv_path, "bin", "python3")
command = [python3_interpreter, script_path] + list(args)
result = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
out, err = result.communicate()
if result.returncode != 0:
raise RuntimeError("Subprocess returned an error: " + err.decode())
return out.strip().decode()

if name == "main":
try:
venv_path = "/path/to/py3env" # Path to your Python 3.x virtual environment
output = run_python3_script(venv_path, "example.py", "10")
print("Output from Python 3 script:", output)
except Exception as e:
print("An error occurred:", str(e))

#Example of python3 script

example.py (Python 3.x script)

import sys
import numpy as np

def py3_function(x):
arr = np.array([x])
print(f"Running in Python 3.x with argument {x}")
return arr[0] * 2

if name == "main":
x = int(sys.argv[1])
result = py3_function(x)
print(result)