Cheuk Ting Ho
Developer advocate / Data Scientist - support open-source and building the community.
Python Zero to Heros
Online Absolute Beginner Python Tutorials
Every Sunday 2pm (UK time/ BST)
by Cheuk Ting Ho
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
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
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
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)
There are also Mid Meet Py every Wednesday 6pm
Python OS and Subprocessing
By Cheuk Ting Ho
