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Core Python for Data Engineers

The language you will write almost every pipeline in.

Start from zero: what data engineering is, Python basics, file handling, APIs, and a production ingest capstone. No prior experience needed.

25 lessons9 modules5 stages4h 44m
Start lesson 1What is data engineering?

Core foundational modules are free. Advanced production modules need Pro.

Why this track exists

A company has data in a hundred places: a CSV a vendor emails every morning, a payments API, a database another team owns. Somebody has to fetch it, fix the broken rows, and put it somewhere useful, on a schedule, without being woken up at 3 a.m. every time it fails. Doing that by hand does not scale past a week. Python is how you write it down once and let a machine repeat it.

Most data engineering job posts list Python first. In practice you use a small slice of it constantly: read a file, loop over records, call an API, handle the error, write a log line, exit with the right code. This track teaches that slice properly instead of teaching the whole language badly.

What you need before starting

  • Nothing about programming

    This track starts at what a variable is. If you can use a computer and type, you have enough.

  • Nothing about data engineering

    The first lesson explains what the job actually is before any code appears.

The roadmap

5 stages, in the order they build on each other. Each stage lists the modules and lessons it covers, and what you should be able to do by the end of it.

01Orientation

Before writing code, understand what a data engineer is paid to do and why Python is the tool. Skipping this is why beginners write scripts with no idea what problem they serve.

Getting StartedFree

0/2

What data engineering is, why Python is the language of choice, and how this track works.

  1. What is data engineering?10m
  2. Why Python for data engineers?8m

By the end of this stage

You can explain in your own words what a pipeline is and what part of it Python handles.

02The language core

Every transformation you will ever write is built from four things: values, decisions, repetition, and functions. Get these solid and the rest of the track is just vocabulary.

FoundationsFree

0/2

Variables, types, data structures, and the building blocks of every Python program.

  1. Variables, types & type hints8m
  2. DE data structures12m

Module Checkpoint

2 conceptual questions to verify mastery

Flow, functions & files

0/5

Loops, retries, reusable utilities, and reading warehouse files safely.

  1. Control flow & error handling10m
  2. Functions, modules & imports10m
  3. Strings and text10m
  4. File I/O & data formats12m
  5. Working with JSON10m

By the end of this stage

You can read a CSV off disk, loop through it, clean each row, and write the result back out.

Where people get stuck

Dictionaries and lists of dictionaries are the shape almost all pipeline data takes. If that shape still feels fuzzy, redo the exercises before moving on. Everything later assumes it.

03Real data sources

Files on your laptop are the easy case. Real sources are HTTP APIs that paginate, time zones that lie, and fields that are sometimes null and sometimes the string 'null'.

APIs, streams & objectsFree preview

0/3

Talk to services, stream huge files, and model connectors as classes.

  1. Working with REST APIs12m
  2. Iterators & generators (yield)Free12m
  3. OOP for pipeline engineering12m

Module Checkpoint

1 conceptual questions to verify mastery

Time & validation

0/2

UTC intervals and rejecting dirty rows before they hit the lake.

  1. Working with dates & timestamps10m
  2. Data validation with Pydantic12m

By the end of this stage

You can pull data from a REST API page by page, parse timestamps correctly, and reject records that fail validation instead of silently corrupting the output.

Where people get stuck

Time zones and naive datetimes cause more production bugs than any other single thing in this stage. Slow down on that lesson.

04Code that survives production

A script that works once is not a pipeline. A pipeline runs unattended, fails safely, retries the transient errors, and does not double-write when it runs twice.

Text & PatternsFree preview

0/2

Parse logs and survive encoding surprises at the ingest boundary.

  1. Regular expressions for logsFree12m
  2. String encoding & unicode gotchas12m

Reliable Pipelines

0/4

Logging, cleanup, retries, and an honest mental model of concurrency.

  1. Logging instead of print-debugging12m
  2. Context managers & resource cleanup10m
  3. Retries, backoff, and idempotency14m
  4. Concurrency, asyncio, and the GIL14m

Module Checkpoint

1 conceptual questions to verify mastery

Packaging & Config

0/3

Twelve-factor config, pinning, and a CLI entrypoint, including what this browser cannot do.

  1. Config & secrets management10m
  2. Dependency management & pinning10m
  3. Building a pipeline CLI12m

By the end of this stage

You can write a job with logging, retries with backoff, config separated from code, and idempotent behaviour on rerun.

Where people get stuck

Idempotency is the concept most people nod along to and then get wrong. If you cannot explain what happens when your job runs twice on the same input, you have not got it yet.

05Tests and the capstone

The difference between a script and something a team will let near production is usually a test suite and a clean entrypoint.

Testing & Capstone

0/2

Prove transforms with tests, then assemble an ingest script that uses the whole track.

  1. Unit testing data transforms12m
  2. Capstone: ingest script end to end18m

By the end of this stage

You finish with an ingest job you can put in a repo and talk about in an interview: it takes a real source, validates, transforms, loads, logs, and has tests.

How you know it worked

Finishing the lessons is not the goal. These are the things you should be able to do afterwards, and each one is worth checking honestly.

  • You can read a messy CSV and produce a clean list of records without looking anything up.
  • You can call a paginated REST API and handle a failed request without crashing the job.
  • You can explain, out loud, what makes a pipeline idempotent and why anyone cares.
  • You have an ingest capstone in a repo, with tests, that you would be happy to screen share.

How long it takes

30 minutes a day

about 10 sessions

1 hour a day

about 5 sessions

4 hours a weekend day

about 2 sessions

Do not batch this track into long sessions. One lesson plus its exercise per sitting beats four lessons read passively. If you are new to programming, expect the Foundations stage to take twice as long as the estimate, and that is normal.

These counts cover reading and the built-in exercises only. Real practice on the drills and a capstone will add to it, and that time is where most of the learning happens.

What interviewers are really testing

  • Whether you write a loop that handles the failure case, or only the happy path.
  • Whether you reach for a dictionary or a list of tuples, and can say why.
  • Whether you know what happens on rerun. Interviewers ask 'what if this runs twice?' to separate script writers from pipeline writers.
  • Whether you log something useful, or print debug lines and call it observability.

Mistakes to avoid on this track

Common mistakes on this track and what to do instead
Common mistakeWhat to do instead
Learning Python from a general tutorial that spends three weeks on classes and decorators.Data engineering Python is mostly files, dicts, requests, and error handling. Learn that first, and go deeper only when a real problem needs it.
Reading lessons without running the exercises.The exercises are where the learning happens. Reading code gives you recognition, writing it gives you recall, and interviews test recall.
Catching every exception with a bare except and moving on.That turns a loud failure into silent data loss. Catch the error you expect, and let the ones you did not expect crash the job so you find out.

Where to practise this

Python drills in Studio

Timed problems on the same data shapes the lessons use.

Interview drills

SQL, Python, and PySpark problems that show up in DE interviews.

Where to go after this

SQL & Analytical Warehousing

Python moves the data, SQL is how anyone asks it questions. These two together are the actual floor for the job.

Pandas for Data Manipulation

The same transformations you hand-wrote in loops, done in a few lines on a DataFrame.

All tracksFull data engineering roadmap45-day plan

Core Python for Data Engineers reviews & rating

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