Prove your Python skills
Almost every CV lists Python, so the word alone tells a hiring manager very little. Lemma records how you actually use it: code you debug live, assessments that adapt to you, and repositories you connect.
Preparing for an interview? Python interview questions, junior to senior
What Python competence looks like
A competent Python developer writes code other people can read a month later. They reach for the standard library before adding a dependency, use comprehensions and generators where they clarify rather than show off, and know when a dict lookup beats a loop. They add type hints to the parts of a codebase that other people call.
They also debug calmly. Given a failing script, they read the traceback from the bottom, reproduce the bug in isolation and fix the cause rather than the symptom. They manage environments and dependencies deliberately, write tests that pin behaviour down, and can explain why a piece of code is slow before they try to make it faster.
Live debugging of a failing script
60 min · Learning · with Ravi T.
Ravi T. rated the session
Practitioner · after the call
Clear reasoning on idiomatic core language. Talked through trade-offs first.
Idiomatic core language
Comprehensions, unpacking, context managers and generators used where they make the code clearer, not cleverer.
Data structures
Choosing between lists, dicts, sets, tuples and dataclasses based on access patterns and mutability.
Type hints
Annotating public functions, using generics and protocols, and running a type checker as part of the workflow.
Testing with pytest
Fixtures, parametrised tests and mocking at the right boundary so tests stay fast and meaningful.
Packaging and environments
Virtual environments, pinned dependencies and project layout that another developer can install without guessing.
Async and concurrency
Knowing when asyncio, threads or processes fit the workload, and how the GIL shapes that choice.
What counts as evidence of Python skills?
A line on a CV saying Python is a claim. A reviewed session, an assessed level or a repository linked from your account is evidence. These are the kinds Lemma records against your Python skill, each with where it came from. See the evidence methodology for how each source is weighed.
Python
Diego A. · SCI recomputed 9 Oct
Evidence · 4 entries
- Rated 5.0
Live debugging of a failing script
Live session · 9 Oct
- Level 7.2
Adaptive Python scenario questions
Adaptive assessment · 2 Oct
- Verified
A connected Python repository
GitHub connector · 24 Sep
- Taught · 1.5x
Teaching a Python session
Live session · 11 Sep
Live debugging of a failing script
In a one-to-one session you work through a broken Python program with a practitioner. They see how you read tracebacks, isolate the fault and explain the fix, then rate the session.
Adaptive Python scenario questions
Multiple-choice questions built around realistic situations, such as a snippet with a mutable default argument, ask you to pick the correct diagnosis. Difficulty adjusts after each answer, and harder questions count for more.
A connected Python repository
Connect a GitHub repository or a specific commit you wrote, such as a library, a CLI tool or a service. Lemma checks the repository exists and that your account has access to it.
Teaching a Python session
Explaining decorators or generators to someone else shows a depth that answering questions does not. Teaching sessions count for more than learning sessions toward your Python record.
How is a Python skills test run on Lemma?
The Python test runs 15 to 25 questions and adjusts difficulty to your answers, with scenarios from services under real load. The result counts alongside sessions and linked repositories toward your Python SCI, which favours recent evidence over old.
The second call prints ['a', 'b'], not ['b']. Why?
def add(item, items=[]):
items.append(item)
return items
add('a')
print(add('b'))- Aappend returns a new list
- Bitems is a global variable
- CStrings are mutable in Python
- DThe default list is created once and shared
Practise with the AI tutor
Work through Python exercises that adapt as you go, from list manipulation to async code. The tutor remembers what you covered. Drills add only a small, capped amount to your score, so they prepare you rather than prove anything.
Code with a practitioner
Book live sessions where you write, review or debug Python with someone who uses it daily. Both of you rate the session afterwards, and that rating becomes part of your Python evidence.
Take the Python assessment
Answer adaptive scenario questions on scoping, mutability, iteration and error handling, some showing a snippet to diagnose. Harder questions count for more, and time limits with no going back keep it honest.
Python skills: common questions
How do I prove I know Python without a computer science degree?
What does a Python skills assessment test?
Can I show Python for data work and backend work separately?
Is a Python certificate enough to get hired?
Skills related to Python
Browse the skills directoryData analysis
Evidence of how you frame questions, clean data and reach conclusions a decision-maker can rely on.
Evidence for data analysisMachine learning
Show how you frame, train, evaluate and debug models, with evidence a practitioner has reviewed live.
Evidence for machine learningData engineering
Evidence that your pipelines are reliable, testable and recoverable, reviewed by practitioners in live sessions.
Evidence for data engineeringSQL
Prove you can write correct, fast queries on real schemas, from joins to window functions and query plans.
Evidence for SQL
Start your Python evidence record.
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