30 Days Of Python — Administrator & Developer Guide

1. Architecture Overview

30 Days Of Python is a structured Python programming curriculum organized as a Git repository of daily lessons. Each day is a self-contained directory with a markdown tutorial and companion Python scripts. The repository also includes a functional Flask web application (python_for_web/) that serves as both a teaching example and a deployable artifact, plus reusable Python packages (mypackage/, 20_Day_Python_package_manager/) demonstrating package creation concepts.

The project is a monorepo combining educational content (markdown), executable code examples (Python scripts), sample data files (CSV/JSON/TXT), and a web application — all organized around a 30-day progression.

Component Inventory

Technology Stack

Note

The pinned Flask version (1.1.1) is several major versions behind current (Flask 3.x). This is intentional for stability of the teaching example but means the web app uses deprecated patterns such as SEND_FILE_MAX_AGE_DEFAULT configuration.

Data Flow

Learner reads daily markdown lesson
  → Runs companion .py file(s) to see concepts in action
  → Completes exercises at end of markdown
  → Progresses to next day

Flask app (Day 26):
  Browser → GET / → app.py:home() → home.html (techs list)
  Browser → GET /about → app.py:about() → about.html
  Browser → GET/POST /post → app.py:post() → post.html / redirect to /result
  Browser → GET /result → app.py:result() → result.html

2. System Requirements

Optional Software (by lesson day)

3. Configuration Reference

Config Files

Environment Variables

Important

The PORT environment variable is the only runtime configuration. It is read in python_for_web/app.py via os.environ.get("PORT", 5000). All other behavior is hardcoded in the example scripts.

Flask Application Configuration

The Flask app sets one configuration value programmatically:

app.config['SEND_FILE_MAX_AGE_DEFAULT'] = 0

This disables static file caching during development. The app also runs with debug=True and binds to 0.0.0.0, which is appropriate for local development but not for production deployment.

4. Deployment & Scaling

Local Development

No deployment steps are required for the core curriculum. Clone and run:

git clone https://github.com/Asabeneh/30-Days-Of-Python.git
cd 30-Days-Of-Python

Flask App Deployment

The python_for_web/ directory includes a Procfile, indicating it was designed for Heroku deployment:

web: python app.py

Warning

The Flask app runs with debug=True and binds to 0.0.0.0. For any deployment beyond local learning, disable debug mode and configure a proper WSGI server (Gunicorn, uWSGI) in front of the Flask app.

Heroku deployment:

1. Create a Heroku app
2. Push the python_for_web/ directory
3. The Procfile and requirements.txt handle the rest

Docker deployment (custom):

FROM python:3.10-slim
WORKDIR /app
COPY python_for_web/ .
RUN pip install -r requirements.txt
EXPOSE 5000
CMD ["python", "app.py"]

Hosting the Curriculum

For classroom or workshop use, the markdown files can be served via:

• GitHub Pages — push to a gh-pages branch
• MkDocs — add a mkdocs.yml and build a static site
• Raw GitHub — link directly to markdown files on GitHub (renders natively)

5. Operations

Content Update Workflow

To update lesson content:

1. Edit the relevant day's markdown file
2. If code examples changed, update the corresponding .py file
3. If translations exist for the changed day, flag them for translation update

Tip

The Spanish translation includes actual .py code files (Spanish/01_Day_Introduction/helloworld.py, Spanish/02_Day_Variables_builtin_functions/variables.py, Spanish/03_Day_Operators/day-3.py). Other translations only have markdown. When updating code examples, check if Spanish .py files need updating too.

Translation Management

Note

The Persian directory is spelled Persain/ (sic) throughout the repository. This is a known typo but renaming it would break existing links and forks.

Monitoring Content Quality

Known community-reported issues to track:

6. Performance

Repository Size

The data/ directory contributes the bulk of file size (242,022 characters) due to large CSV and JSON datasets (Hacker News posts, Fortune 500 companies, cat breeds API data, country information).

Tip

If forking for a trimmed version, the data/ directory, images/, and translation directories are the largest space consumers. The core English curriculum (Days 1–30) plus python_for_web/ and mypackage/ are under 50KB of source.

7. Security

Flask Application Security Considerations

The python_for_web/app.py has several security-relevant characteristics:

Caution

The Flask application is a teaching example and should never be deployed to a public-facing server without significant hardening: disable debug mode, add CSRF protection, implement input validation, use a production WSGI server, and configure proper security headers.

Dependency Security

The pinned dependencies in requirements.txt are from 2019:

For any use beyond local learning, update all dependencies to their latest versions.

Data Files

The data/ directory contains only public/synthetic datasets. No credentials, API keys, or sensitive information is present in the repository.

8. Developer Internals

Repository Structure

30-Days-Of-Python/
├── .gitignore
├── mymodule.py                          # Root-level module example (Day 12)
├── numpy.md                             # NumPy reference notes
├── readme.md                            # Project README
│
├── 01_Day_Introduction/                 # Day 1: Python basics
│   └── helloworld.py
├── 02_Day_Variables_builtin_functions/   # Day 2: Variables
│   ├── 02_variables_builtin_functions.md
│   └── variables.py
├── 03_Day_Operators/                    # Day 3: Operators
│   ├── 03_operators.md
│   └── day-3.py
├── 04_Day_Strings/                      # Day 4: Strings
│   ├── 04_strings.md
│   └── day_4.py
├── 05_Day_Lists/                        # Day 5: Lists
│   ├── 05_lists.md
│   └── day_5.py
├── 06_Day_Tuples/ through 30_Day_Conclusions/  # Days 6-30
│   └── {NN}_{topic}.md                  # Markdown lesson (all days)
│   └── [optional .py file]             # Code examples (some days)
│
├── 12_Day_Modules/                      # Day 12: Modules
│   ├── 12_modules.md
│   ├── main.py                          # Entry point importing mymodule
│   └── mymodule.py                      # Local copy of root mymodule
│
├── 20_Day_Python_package_manager/       # Day 20: Packages
│   ├── 20_python_package_manager.md
│   ├── __init__.py
│   ├── arithmetic.py                    # Math functions
│   └── greet.py                         # Greeting function
│
├── mypackage/                           # Standalone package example
│   ├── __init__.py
│   ├── arithmetics.py                   # Math functions (mirrors Day 20)
│   └── greet.py                         # Greeting function
│
├── python_for_web/                      # Day 26: Flask web app
│   ├── .gitignore
│   ├── Procfile                         # Heroku deployment
│   ├── app.py                           # Flask application entry point
│   ├── requirements.txt                 # Pinned dependencies
│   ├── static/css/main.css              # Stylesheet
│   └── templates/                       # Jinja2 templates
│       ├── layout.html                  # Base template
│       ├── home.html                    # Home page
│       ├── about.html                   # About page
│       ├── post.html                    # Text input form
│       └── result.html                  # Analysis result
│
├── data/                                # Sample datasets
│   ├── cats.json                        # Cat breeds (API example)
│   ├── countries_data.json              # Country information
│   ├── countries_data_long.json         # Extended country data
│   ├── countries.py                     # Country lists as Python
│   ├── countries-data.py                # Country data as Python
│   ├── stop_words.py                    # Stop words list
│   ├── *.csv                            # Various CSV datasets
│   └── *.txt                            # Text files for exercises
│
├── files/                               # File handling examples
│   ├── csv_example.csv
│   ├── json_example.json
│   ├── xml_example.xml
│   ├── example.txt
│   ├── reading_file_example.txt
│   └── excel_example.xlsx
│
├── images/                              # Instructional screenshots
│   ├── *.png                            # IDE, shell, concept diagrams
│   └── mongoDB/                         # MongoDB Atlas setup screenshots
│
├── Chinese/                             # Chinese translation
├── Korean/                              # Korean translation (partial)
├── German/                              # German translation
├── Spanish/                             # Spanish translation (with code)
├── Persain/                             # Persian translation
├── Portuguese/                          # Portuguese translation (minimal)
├── Ukrainian/                           # Ukrainian (readme only)
│
├── old_files/                           # Legacy multi-day READMEs
├── numpy_files/                         # NumPy lesson images
└── test_files/                          # Test output images

Module Reference

mymodule.py (Root)

A teaching module demonstrating Python module creation. Exists in two locations with identical functionality:

Exported symbols:

mypackage/ Package

Demonstrates Python package creation with __init__.py.

mypackage/arithmetics.py:

mypackage/greet.py:

Note

The 20_Day_Python_package_manager/ directory contains arithmetic.py and greet.py with identical functionality to mypackage/arithmetics.py and mypackage/greet.py. The only difference is the filename: arithmetic.py (Day 20) vs. arithmetics.py (mypackage). Both also include an __init__.py.

python_for_web/app.py — Flask Application

A Flask web application with 4 routes serving Jinja2 templates:

Application configuration:

app = Flask(__name__)
app.config['SEND_FILE_MAX_AGE_DEFAULT'] = 0  # Disable static file caching

Startup:

port = int(os.environ.get("PORT", 5000))
app.run(debug=True, host='0.0.0.0', port=port)

Warning

The /post POST handler reads request.form['content'] but does not pass it to the redirect target (/result). The analyzed content is discarded. This appears to be an intentional exercise gap for learners to complete.

Code Patterns and Conventions

Naming:

• Day directories: {NN}_Day_{Topic}/ with underscores (e.g., 04_Day_Strings/)
• Markdown files: {NN}_{topic}.md (lowercase, underscores)
• Python files: inconsistent — helloworld.py, day_4.py, day-3.py, variables.py
• Translation files: {NN}_{topic}_{lang_code}.md (e.g., 03_operators_de.md)

Code style:

• No type hints used anywhere
• Inline comments extensively used to explain each line
• Print statements used for all output (no logging)
• No unit tests
• No linting configuration
• Snake_case for variables and functions (Python convention)

Duplicate code:

The following code is duplicated between locations:

This duplication is intentional — each copy exists in its lesson context for standalone execution.

Data Files Reference

data/ directory — large datasets:

files/ directory — small teaching examples:

Note

The json_example.json file contains a typo: "JavaScrip" instead of "JavaScript". This exists in the source and may be intentional as a teaching moment about data validation.

Testing Strategy

The repository contains no automated tests. The .py files in each day's directory serve as executable examples that demonstrate correct behavior through print() output. Verification is manual — the learner compares console output against the inline comments.

Recommended additions for contributors:

• Add pytest configuration and unit tests for mypackage/ functions
• Add integration tests for the Flask application routes
• Add a CI pipeline to validate Python syntax across all .py files

Potential Improvements

1. Consolidate duplicate code — mypackage/ and 20_Day_Python_package_manager/ contain identical function implementations. Consider having Day 20 reference mypackage/ directly or documenting the intentional duplication.

2. Update Flask dependencies — The pinned versions (Flask 1.1.1, Werkzeug 0.16.0) have known security vulnerabilities. Update to Flask 3.x for learners who might deploy the example.

3. Add automated testing — A simple CI workflow validating Python syntax (python -m py_compile *.py) would catch syntax errors. Some existing code has bugs (e.g., fruits.list(3, 'lime') in Day 5 should be fruits.insert(3, 'lime'); fruits.remove() should be fruits.pop()).

4. Fix known code errors:

   • 05_Day_Lists/day_5.py: fruits.list(3, 'lime') → should be fruits.insert(3, 'lime')
   • 05_Day_Lists/day_5.py: fruits.remove() → should be fruits.pop()
   • 04_Day_Strings/day_4.py: area = pi # radius ## 2 → broken expression (should be pi * radius ** 2)

5. Standardize Python file naming — Current mix of helloworld.py, day_4.py, day-3.py, variables.py is inconsistent. A convention like day_{NN}.py would improve navigation.

6. Complete translation coverage — Korean (5 days) and Portuguese (1 day) translations are fragmentary. Either complete them or mark them clearly as "work in progress."

7. Fix the /post route — The Flask app captures form content but discards it on redirect. Either implement the text analysis or document it explicitly as an exercise.

8. Add a unified requirements.txt — A root-level requirements file covering all lessons (Flask, beautifulsoup4, requests, numpy, pandas, pymongo) would simplify setup.

9. Fix the Persain/ directory name — The Persian translation directory is misspelled. A rename to Persian/ with a symlink for backward compatibility would be clean.

Contributing Guide

The repository accepts community contributions primarily through GitHub issues. Based on the issue history:

• Content corrections (typos, wrong examples) are the most common contribution type
• Issues #565, #795, #796, #797, #807, #808, #813, #823 all report content errors
• Translation contributions follow a directory-per-language pattern

To contribute:

1. Fork the repository
2. Create a branch for your change
3. Follow the existing naming conventions for the relevant language/day
4. Open a pull request with a clear description of the correction

Tip

When contributing code fixes, verify the .py file output matches the inline comments. Several existing scripts have mismatches between code behavior and comments (e.g., Day 4 string examples have dead code fragments).

9. Integration Points

Flask Template System

The Flask app uses Jinja2 templates with a layout inheritance pattern:

templates/
├── layout.html    # Base template (HTML structure, CSS link)
├── home.html      # Extends layout, renders tech list
├── about.html     # Extends layout, about page
├── post.html      # Extends layout, text input form
└── result.html    # Extends layout, analysis results

Static assets are served from python_for_web/static/css/main.css.

Heroku Integration

The Procfile in python_for_web/ declares a web process:

web: python app.py

Combined with requirements.txt, this provides Heroku buildpack auto-detection for Python applications.

MongoDB Atlas (Day 27)

The Day 27 lesson references MongoDB Atlas (cloud-hosted MongoDB). Setup screenshots are provided in images/mongoDB/:

External APIs (Day 28)

The Day 28 lesson teaches consuming REST APIs. The included data/cats.json contains sample data from TheCatAPI, providing offline practice data for learners without API access.