Python Zero to Heros

Online Absolute Beginner Python Tutorials

Every Sunday 2pm (UK time/ BST)

twitch.tv/cheukting_ho

by Cheuk Ting Ho

@cheukting_ho

https://cheuk.dev

Cheukting

Get this slide deck:

slides.com/cheukting_ho/python-os-subprocess

Recap

Beginner topics:

Python objects, Control flows,

Functions, modeuls, classes and decorators

strings operations and regex with re

Testing:

pytest with fixtures and mock

property-based testing

python linters & auto-formatters

TDD, type hinting

Intermedite topics:

Iterators, generators, async

Packaging:

generating docs, pypi

Others:
Functional Programming

Read and Write a file

In Python you can use open() to get access to a file

https://www.w3schools.com/python/python_file_handling.asp

open() returns a file object which provide lot's of various operations

https://www.programiz.com/python-programming/file-operation

os — Miscellaneous operating system interfaces

This module provides a portable way of using operating system dependent functionality.

Various OS operations

Creating Directory
Changing the Current Working Directory
Removing a Directory
List Files and Sub-directories

https://www.tutorialsteacher.com/python/os-module

os.path — Common pathname manipulations

https://docs.python.org/3/library/os.path.html#module-os.path

os.path methods

os.path.abspath(path)
os.path.realpath(path)
os.path.dirname(path)
os.path.join(path, *paths)

subprocess — Subprocess managemen

The subprocess module allows you to spawn new processes, connect to their input/output/error pipes, and obtain their return codes.

Using subprocess

https://docs.python.org/3/library/subprocess.html

output = subprocess.run(
  [
    "docker-compose",
    "--file",
    os.path.dirname(os.path.realpath(__file__)) + "/test-docker-compose.yml",
    "up",
    "-d",
  ],
  stderr=subprocess.PIPE,
)
if output.returncode != 0:
  raise RuntimeError(output.stderr)

Next week:
TBC

Sunday 2pm (UK time/ BST)