Question 1

What is asyncio.TaskGroup and why does it replace gather?

Accepted Answer

**Target Audience:** Developers who have written `asyncio` code with `gather` or `create_task` and want to know what TaskGroup changes and when to pick which.
**Difficulty:** Medium
**Python version:** `TaskGroup` needs Python 3.11+. Behaviour checked on CPython 3.11, 3.12 and 3.13 (same output); both examples also run in this page on Pyodide 0.25.1 (CPython 3.11.3).

> **How to read this doc:** Every idea comes in plain language first. Words an interviewer expects you to use are tagged `📌 Inte

Question 2

How do you raise and split ExceptionGroups manually?

Accepted Answer

**Target Audience:** Python developers who have seen `ExceptionGroup` come out of a `TaskGroup` and want to create, inspect and split groups themselves.
**Difficulty:** Medium
**Python version:** Python 3.11+ (PEP 654). Behaviour checked on CPython 3.11, 3.12 and 3.13 (identical output); both examples run in this page on Pyodide 0.25.1 (CPython 3.11.3).

> **How to read this doc:** Every idea comes in plain language first. Words an interviewer expects you to use are tagged `📌 Interview term:` a

Question 3

What is except* and ExceptionGroup in Python 3.11+?

Accepted Answer

**Target Audience:** Python developers who know try/except and are meeting exception groups for the first time
**Difficulty:** Medium
**Python version:** `ExceptionGroup` and `except*` need Python 3.11+; checked on CPython 3.11 (and in this page on Pyodide 0.25.1, which is CPython 3.11.3), the asyncio example on CPython 3.12

> **How to read this doc:** Each idea is explained in plain language first, then tagged with `📌 Interview term:` so you also learn the exact word an interviewer expects. E

Question 4

How does TaskGroup handle cancellation and ExceptionGroup?

Accepted Answer

**Target Audience:** Developers who already use `asyncio.TaskGroup` and need the precise cancellation rules for production code and for interviews.
**Difficulty:** Hard
**Python version:** Checked on CPython 3.11, 3.12 and 3.13 (identical output for both examples); both run in this page on Pyodide 0.25.1 (CPython 3.11.3). Source-code references are to `Lib/asyncio/taskgroups.py` as installed with CPython 3.11 and 3.13.

> **How to read this doc:** Every idea comes in plain language first. Words

PYTHONDECODED.

Medium

What is asyncio.TaskGroup and why does it replace gather?

How do you raise and split ExceptionGroups manually?

What is except* and ExceptionGroup in Python 3.11+?

Hard

How does TaskGroup handle cancellation and ExceptionGroup?