Python Tutorials for Practical Learning

Pytest Assert Function Called With Mock

July 14, 2026January 1, 2024

Pytest assert function called guide showing Mock assert_called_once call arguments and test verification steps

Learn how to assert function calls in pytest with unittest.mock, choose the right call assertion, patch the correct import, and test side effects.

Remove a Python venv Safely: Deactivate and Delete

July 13, 2026January 1, 2024

Remove Python venv guide showing deactivate verify delete folder and clean project references

Remove a Python venv safely by leaving the active shell, confirming the environment path, deleting only the environment directory, and cleaning stale editor references.

Fix f-string Unmatched Errors in Python

July 14, 2026May 30, 2023

Fix f-string unmatched syntax errors in Python

Fix f-string SyntaxError messages by checking quote boundaries, replacement braces, backslashes, and the Python version.

Python Type Hints with rtype: Runtime Validation and Limits

July 13, 2026May 30, 2023

Use Python type hints and rtype-style runtime validation to document contracts, catch invalid values at boundaries, and keep static and runtime checks distinct.

Python split(): Separator, Whitespace, and maxsplit

July 13, 2026May 30, 2023

Python split method guide showing a string separated into list items

Understand Python split() whitespace rules, delimiters, empty fields, maxsplit, splitlines(), and when to use a real parser.

Python heapq: Min-Heap, Priority Queue, and Top-k

July 13, 2026May 30, 2023

Python heapq module priority queue guide

Build Python min-heaps, push and pop priorities, handle ties, select top-k values, and understand why a heap is not fully sorted.

Python str.translate(): Replace, Delete, and Normalize Characters

July 13, 2026May 30, 2023

Python translate str.maketrans replace remove characters

Use Python str.translate() and str.maketrans() to replace or delete characters, normalize text, and distinguish character mapping from language translation.