Python Fundamentals: Complete Learning Roadmap
Welcome to your second brain Python reference library. This page organizes 11 comprehensive guides into a structured learning path. Follow this sequence to build unshakeable Python fundamentals before Le Wagon bootcamp (October 2026).
📍 Quick Navigation
Start here based on your level:
- 🟢 Beginner (haven’t coded much): Start with TIER 1
- 🟡 Intermediate (coded before): Start with TIER 2
- 🔴 Advanced (need just the gaps): Jump to TIER 3
🎯 TIER 1: Core Language Fundamentals (Weeks 1-4)
Build the mental models you’ll use every day. Master these before touching data libraries.
| # | Topic | Page | Time | Learn |
|---|---|---|---|---|
| 1 | Loops: for & while | Python-Loops | 2h | When to repeat code, mental models for iteration |
| 2 | Control Flow: if/elif/else | Python-Control-Flow | 2h | Decision-making logic, boolean operators, ternary |
| 3 | Functions & Modules | Python-Modules-Functions-Lists | 2.5h | Code organization, reusability, imports |
| 4 | Lists (The Workhorse) | Python-Modules-Functions-Lists | 2.5h | Indexing, slicing, methods, list operations |
| 5 | List Comprehensions | Python-List-Comprehensions | 2h | Pythonic transformations, filtering, performance |
| 6 | Data Structures | Python-Data-Structures | 2h | Lists, dicts, sets, tuples—when to use each |
Subtotal: ~13 hours
After TIER 1 you can: Write clean functions, loop over data, understand basic Python code.
🚀 TIER 2: Production-Grade Fundamentals (Weeks 5-8)
Now write code that doesn’t crash. Add safety nets, clarity, and robustness.
| # | Topic | Page | Time | Learn |
|---|---|---|---|---|
| 7 | Type Hints (Advanced) | Python-Type-Hints-Advanced | 2.5h | Optional, Union, Callable, mypy validation |
| 8 | String Formatting & Methods | Python-String-Formatting | 2h | F-strings, parsing CSVs, data validation |
| 9 | Error Handling & Exceptions | Python-Error-Handling | 2.5h | try/except/finally, custom exceptions, retry logic |
Subtotal: ~7 hours (cumulative: ~20 hours)
After TIER 2 you can: Write production-grade functions, validate data, handle failures gracefully, log events.
🏗️ TIER 3: Data Engineering Patterns (Weeks 9-12)
Integrate everything. Build real ETL pipelines and understand distributed computing.
| # | Topic | Page | Time | Learn |
|---|---|---|---|---|
| 10 | OOP: Classes & Objects | Python-Classes-and-OOP | 3h | Design patterns, encapsulation, inheritance |
| 11 | Python for Data Engineering | Python-for-Data-Engineering | 3h | pandas, ETL patterns, PySpark, production practices |
Subtotal: ~6 hours (cumulative: ~26 hours)
After TIER 3 you can: Build complete ETL pipelines, understand Airflow operators, scale to Spark.
📊 Learning Path by Goal
Goal: “I just need bootcamp basics”
Follow TIER 1 only (~13 hours)
Time to complete: 2 weeks
Bootcamp readiness: 70%
Goal: “I want to be job-ready”
Follow TIER 1 + TIER 2 (~20 hours)
Time to complete: 1 month
Bootcamp readiness: 90%
Goal: “I want to master data engineering”
Follow TIER 1 + TIER 2 + TIER 3 (~26 hours)
Time to complete: 2 months
Bootcamp readiness: 100% + ahead of class
🗓️ Le Wagon Timeline Alignment
Before Bootcamp Starts (Oct 31, 2026)
| Milestone | Date | What to Know | Pages |
|---|---|---|---|
| Complete TIER 1 | By Aug 31 | Functions, loops, lists | 1-6 |
| Complete TIER 2 | By Sep 30 | Type hints, error handling | 7-9 |
| Start TIER 3 | By Oct 15 | Basic OOP, pandas intro | 10-11 |
During Bootcamp (Nov 2026 - March 2027)
Weeks 1-2:
You already know loops/functions → focus on pandas & SQL joins
Reference: Python-for-Data-Engineering
Weeks 3-4:
Learn Airflow orchestration (builds on classes/OOP)
Reference: Python-Classes-and-OOP
Weeks 5+:
PySpark, distributed processing, production patterns
Reference: Python-for-Data-Engineering (Tier 2: Scaling section)
📝 Study Strategy
Daily Workflow (60 min/day)
Week 1-4 (TIER 1):
├─ 40 min: Read + code examples from page
├─ 15 min: Complete mini-project (if provided)
└─ 5 min: Update your own notes
Week 5-8 (TIER 2):
├─ 30 min: Read advanced concepts
├─ 20 min: Apply to your own code
└─ 10 min: Refactor old projects with new knowledge
Week 9-12 (TIER 3):
├─ 30 min: Read data engineering patterns
├─ 25 min: Build small ETL project
└─ 5 min: Document learnings
How to Use This Roadmap
- Start with TIER 1, Page 1 → Read until you understand the concept
- Code along → Copy examples, modify them, break them intentionally
- Mini-project → If page has one, complete it (weather ETL, etc.)
- Link references → Click
[[Related]]links when you need context - Consolidate → Review one page per week once you’ve finished TIER 1
🎓 Before You Start: Prerequisites Check
You should be able to answer “yes” to all:
- Can you write
x = 5; print(x)and understand what happens? - Do you know what
if,for,whilekeywords do (roughly)? - Can you explain what a function is (takes input, returns output)?
- Are you comfortable with the command line (running
python script.py)?
If any are “no”: Spend 2 hours on Codecademy Python basics first, then come back here.
🚨 Common Pitfalls (Don’t Fall Into These!)
| Pitfall | Why It Matters | Fix |
|---|---|---|
| Skipping TIER 1 basics | You’ll get confused later | Discipline yourself to master loops/functions first |
| Not coding the examples | Reading ≠ learning programming | Type every code block, modify it, break it |
| Ignoring type hints | Production code breaks silently | Type hints catch bugs early (mypy helps) |
| Not understanding errors | You’ll waste hours debugging | Read error messages carefully; they tell you what’s wrong |
| Forgetting try/except | Scripts crash in production | Error handling is not optional (see TIER 2) |
✅ Consolidation Checklist
After completing each TIER, verify your knowledge:
After TIER 1
- Write a function that loops through a list and returns transformed results
- Use list comprehensions instead of loops
- Explain when to use a
whileloop vs. aforloop - Create a dict, access keys, iterate items
- Use
if/elif/elsewithand/oroperators
After TIER 2
- Add type hints to your functions (int, str, list[dict])
- Parse a CSV line into a dict using
.split()and.strip() - Wrap code in try/except and handle specific exceptions
- Write a custom exception class
- Use f-strings with formatting (e.g.,
f"{value:.2f}")
After TIER 3
- Design a class with
__init__and methods - Create a simple pandas DataFrame from a list of dicts
- Write a complete ETL function: extract → transform → load
- Add logging to your pipeline
- Explain when to use pandas vs. PySpark
📚 Full Page Directory
| # | Title | Description | Time | Difficulty |
|---|---|---|---|---|
| 1 | Python-Loops | for/while loops, range(), break/continue | 2h | 🟢 Beginner |
| 2 | Python-Control-Flow | if/elif/else, boolean logic, ternary | 2h | 🟢 Beginner |
| 3 | Python-Modules-Functions-Lists | Modules, functions, lists fundamentals | 2.5h | 🟢 Beginner |
| 4 | Python-List-Comprehensions | Pythonic list transformations & filtering | 2h | 🟡 Intermediate |
| 5 | Python-Data-Structures | Lists, dicts, sets, tuples—complete guide | 2h | 🟡 Intermediate |
| 6 | Python-Type-Hints-Advanced | Optional, Union, Callable, mypy | 2.5h | 🟡 Intermediate |
| 7 | Python-String-Formatting | F-strings, string methods, parsing CSVs | 2h | 🟡 Intermediate |
| 8 | Python-Error-Handling | try/except/finally, custom exceptions | 2.5h | 🟡 Intermediate |
| 9 | Python-Classes-and-OOP | Classes, inheritance, encapsulation | 3h | 🔴 Advanced |
| 10 | Python-for-Data-Engineering | pandas, ETL patterns, PySpark | 3h | 🔴 Advanced |
| 11 | Python-oop-bakery-analogy | Interactive OOP tutorial with analogies | 2h | 🟡 Intermediate |
Total: ~26.5 hours
Recommended pace: 1-2 hours/day over 2-3 months
🔗 Cross-Topic Dependencies
┌─────────────────────────────────────────────┐
│ TIER 1: FUNDAMENTALS │
├─────────────────────────────────────────────┤
│ Loops ──┐ │
│ ├─→ List Comprehensions │
│ Control Flow ──→ Loops │
│ Functions ─┐ │
│ ├─→ Modules (code organization) │
│ Lists ──────┘ │
└─────────────────────────────────────────────┘
↓
┌─────────────────────────────────────────────┐
│ TIER 2: PRODUCTION GRADE │
├─────────────────────────────────────────────┤
│ Type Hints (improve functions) │
│ String Methods (parse & validate data) │
│ Error Handling (robust functions) │
└─────────────────────────────────────────────┘
↓
┌─────────────────────────────────────────────┐
│ TIER 3: DATA ENGINEERING │
├─────────────────────────────────────────────┤
│ Classes/OOP (Airflow operators, later) │
│ Data Engineering (pandas, ETL, PySpark) │
└─────────────────────────────────────────────┘
📞 Getting Help
When you’re stuck:
- Check the “Related” section at the bottom of each page
- Search for keywords in all pages (Obsidian search)
- Look at “Tips & Gotchas” — common mistakes are listed
- Code it out — don’t just read; type and run examples
🎯 Final Goal
By the end of this roadmap, you’ll be able to:
✅ Write clean, readable, production-grade Python code
✅ Debug errors confidently
✅ Understand and modify real ETL pipelines
✅ Follow Le Wagon bootcamp from Day 1 without feeling lost
✅ Help teammates review their code