Create venv and config for Python / VS Code

venv_create.py

import fileinput
import os
import venv
from pathlib import Path

# venvtarget = Path('.').resolve().name.replace(' ', '_')
# header = Path(venvtarget / 'Scripts/python.exe').as_posix()
# print(header)

venvtarget = Path(f'.venv')
print(venvtarget)

if not venvtarget.is_dir():
    builder = venv.EnvBuilder(
        system_site_packages=False,
        clear=False,
        symlinks=False,
        upgrade=True,
        with_pip=True
    )

    print(f'Creating new venv in: {venvtarget}')
    builder.create(venvtarget)
    print(f'New venv created in: {venvtarget}')
else:
    print(f'venv exists in: {venvtarget}')


Path('venv_install.py').write_text("""#! template/Scripts/python.exe

import subprocess
import sys
import shlex
import time

from pprint import pprint
from pathlib import Path
from datetime import datetime

now = datetime.now().isoformat()[0:10]  # Date


sequence = [
    f'-m pip install --upgrade pip setuptools wheel',
    f'-m pip install --upgrade -r requirements.txt',
    # f'-m pip freeze',
    ]

try:
    print(sys.executable)
    for line in sequence:
        print()
        print(line)
        process = subprocess.Popen([sys.executable] + shlex.split(line), stdout=subprocess.PIPE)

        while True:
            output = process.stdout.readline()
            if output == b'' and process.poll() is not None:
                break
            if output:
                print(output.strip().decode())
        rc = process.poll()


    # https://stackoverflow.com/a/50255019
    run = subprocess.run([sys.executable] + shlex.split('-m pip freeze'), capture_output=True)
    # pprint(run)
    # print(run.stdout)
    Path(f'./requirements_freeze_{now}.txt').write_bytes(run.stdout)

except subprocess.CalledProcessError as e:
    print(e, run)


input('Done, Press enter to close.')
""")

Path('venv_main_template.py').write_text('#! template/Scripts/python.exe\n')

for line in fileinput.input([Path('venv_main_template.py'), Path('venv_install.py')], inplace=True):
    print(line.replace('template', venvtarget.name), end='')


requirements = Path('requirements.txt')
if not requirements.exists():
    requirements.write_text('pylint\npycodestyle\npydocstyle\nipykernel')
else:
    requirements.touch()


Path('.vscode').mkdir(exist_ok=True)

vscodesettings = Path('.vscode/settings.json')
if not vscodesettings.exists():
    vscodesettings.write_text("""{
    "python.linting.pylintEnabled": true,
    "python.linting.pycodestyleEnabled": true,
    "python.linting.pydocstyleEnabled": true,
    "python.linting.enabled": true
}""")


setupcfg = Path('setup.cfg')
if not setupcfg.exists():
    setupcfg.write_text("""
[pycodestyle]
max-line-length = 160
[pydocstyle]
add-ignore = D100
""")
input('Done, Press enter to close.')

Hello

In the directory you want the code to live in:
Download and run this Gist

This creates a bunch of files
Then run venv_install which installs the Python modules listed in requirements.txt
You can use venv_install again later to install additional modules when you want
If you want to pin dependencies copy requirements_freeze_~date.txt over requirements.txt

Install the VS Code Python extension
Open directory in VS Code

Then create a notebook
Notebooks are particularly useful for exploratory development, as cells of code can be run by pressing ctrl-enter

Python launcher parses shebang-lines to decide what environment to run the program in, this avoids having to use .bat or powershell files to launch Python programs
Use venv_main_template as the #! header for programs

To run a module for example pytest and pytest-html
Copy venv_main_template to run_pytest and add to end of the #!
-m pytest --html=report.html --self-contained-html .