Environment Setup — From Zero to Your First Automation Script

Chapter 1: Environment Setup — From Zero to Your First Automation Script

A well-configured development environment prevents 90% of the problems beginners encounter. This chapter walks from Python version selection through virtual environments, editor configuration, and package management — ending with a real automation script to validate everything. Complete this chapter, and every code example in the rest of the book will run without friction.

Python Version Selection

Recommended: Python 3.11 — it delivers ~25% average performance improvement over 3.10 (per official benchmarks) with mature third-party library support. Python 3.12 works too, but some libraries haven't caught up yet.

Why not 3.9 or below?

• Python 3.10 introduced structural pattern matching (match-case) and cleaner type syntax (int | None instead of Optional[int])
• Python 3.8 reached end-of-life in October 2024 — no more security patches
• Modern automation libraries like Playwright require Python 3.9+ minimum

Check your current version: Run python3 --version (macOS/Linux) or python --version (Windows). If it shows 3.11+, skip installation.

Installation Methods Compared

Virtual Environments: Why venv Is Non-Negotiable

Virtual environments solve a classic problem: Project A needs requests==2.28, Project B needs requests==2.31. Installing globally means they fight over the same space. venv gives each project its own isolated Python installation.

macOS / Linux

# Create virtual environment in project directory
python3 -m venv .venv

# Activate it
source .venv/bin/activate

# Prompt changes to (.venv) — packages install here, not globally

# Deactivate when done
deactivate

Windows

# Create
python -m venv .venv

# Activate (CMD)
.venv\Scripts\activate.bat

# Activate (PowerShell)
.venv\Scripts\Activate.ps1

# If PowerShell blocks execution, run as admin:
# Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser

VS Code Configuration

Essential extensions:

• Python (Microsoft): syntax highlighting, IntelliSense, debugger
• Pylance: advanced type checking and autocomplete
• Ruff: ultra-fast linter + formatter (replaces Black + flake8)

Select your virtual environment interpreter: Press Ctrl+Shift+P (Mac: Cmd+Shift+P), type Python: Select Interpreter, choose .venv/bin/python.

Debug Configuration

Create .vscode/launch.json with the same JSON shown in the Chinese section above (the structure is identical). Press F5 to debug the current file with full breakpoint and step-through support.

Package Management: pip and requirements.txt

Shell

# Install a package
pip install requests

# Install specific version
pip install requests==2.31.0

# Install multiple packages
pip install requests openpyxl pandas

# List installed packages
pip list

# Export current environment to requirements.txt
pip freeze > requirements.txt

# Recreate environment from requirements.txt
pip install -r requirements.txt

# Upgrade pip itself
pip install --upgrade pip

First Automation Script: Bulk Project Directory Creator

Every time you start a new project you manually create the same folder structure. This script creates it in one command — the Chinese section above contains the full annotated code. Here is the usage and key takeaways:

Shell

# Create a project named "my-automation"
python create_project.py my-automation

# Create inside a specific directory
python create_project.py my-automation --dir ~/projects

The script uses three modules you will encounter repeatedly throughout this book:

• pathlib.Path — cross-platform path manipulation; mkdir(parents=True) creates intermediate directories automatically
• argparse — standard library CLI argument parser; provides --help, validation, and default values
• Type hints — project_name: str, base_dir: Path, -> Path throughout; IDE autocomplete and mypy both use these

Checkpoint: If the script runs without errors and produces the directory structure, your environment is correctly configured. Every code example in the rest of the book should work in this same setup.

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Chapter 2: Core Python for Automation