Python basics and development environments

Why this matters

Modern drone work produces more data than anyone can handle by hand. One survey flight can record thousands of telemetry messages, mission planning repeats energy calculations many times, and an automated dock must make decisions on its own. Programming is therefore a basic tool for UAS technologists, as the calculator was for engineers of earlier generations.

This course uses Python because it is easy to read, has data-analysis libraries used worldwide, and has libraries that talk to drones directly, such as pymavlink, which you will use in module 4.

Thinking like a computer

Jeannette Wing (2006) argued that computational thinking is a problem-solving approach everyone should have, not just a programmer’s skill. Many curricula later condensed it into four teachable skills: decomposing a problem, recognising patterns, abstracting away unnecessary detail, and writing a step-by-step solution (an algorithm). That four-part summary comes from later sources; it is not a list in Wing’s original article.

The step beginners skip most is testing with known answers. Before using a program on real data, always try it on an example you can calculate by hand, such as one from another course.

Setting up the environment

Choosing a Python version

On 26 September 2026 the supported Python versions are 3.10 to 3.14 (3.10 reaches end of life around October 2026), and 3.15 is scheduled for 1 October 2026. This course uses Python 3.12–3.14, because the libraries need at least 3.11 and pymavlink has no 3.15 build yet. Check your version with python --version.

Creating a virtual environment

A virtual environment is a folder that keeps each project’s libraries separate, like a personal toolbox for each job. If one project needs an old library version and another needs a new one, they do not clash. Download requirements.txt from the course download page and run, in your work folder:

python -m venv .venv
.venv\Scripts\Activate.ps1          # Windows PowerShell
# source .venv/bin/activate         # Linux or macOS
python -m pip install -r requirements.txt

Once activated, (.venv) appears before the prompt. Activate the venv every time you open a new session. Since Python 3.13, venv writes a .gitignore into the folder, so the environment is not accidentally committed to Git (module 5).

Recommended tools are VS Code for .py files and Jupyter Notebook for step-by-step experiments with plots (see the Jupyter knowledge unit in the drone knowledge hub).

Variables and data types

A variable is a name bound to a value, like a label stuck on a box. Python works out the type itself. The four most common types are:

aircraft = "RSU-QUAD-01"      # str: text
motor_count = 4               # int: whole number
battery_voltage = 22.2        # float: real number (decimal)
armed = False                 # bool: True or False

for value in (aircraft, motor_count, battery_voltage, armed):
    print(type(value).__name__, value)

str RSU-QUAD-01
int 4
float 22.2
bool False

Names that state meaning and unit, such as battery_voltage or altitude_m, keep code readable months later and prevent unit mistakes.

Calculating and converting units

Python uses + - * / as usual; // is floor division, % the remainder and ** a power.

speed_kmh = 54
speed_ms = speed_kmh / 3.6

voltage_v = 22.2
capacity_ah = 8.0
energy_wh = voltage_v * capacity_ah
usable_wh = 0.8 * energy_wh
power_w = 350
endurance_min = usable_wh / power_w * 60

print(f"speed: {speed_ms:.1f} m/s")
print(f"energy: {energy_wh:.1f} Wh, usable: {usable_wh:.1f} Wh")
print(f"endurance: {endurance_min:.1f} min")

speed: 15.0 m/s
energy: 177.6 Wh, usable: 142.1 Wh
endurance: 24.4 min

An f-string starts with f and inserts values in braces {...}. :.1f means one decimal place. It makes results readable without changing the stored value.

Decimals that are not exactly equal

Computers store floats in binary, so a value such as 0.1 is stored only as the nearest representable number. The Python documentation stresses that this is not a bug in Python; it is the nature of binary floating point in every language.

import math

total = 0.0
for _ in range(10):
    total += 0.1

print(total)
print(total == 1.0)
print(math.isclose(total, 1.0))

0.9999999999999999
False
True

Writing code others can read

PEP 8 is the Python style guide used worldwide. Follow these points from day one:

Module lab

Common mistakes

Summary

• Computational thinking means decomposing a problem, designing steps, coding, and testing with known answers
• Use Python 3.12–3.14 and keep each project’s libraries separate with venv
• The basic types are int, float, str and bool; f-strings format results
• Floats cannot store most decimals exactly; compare them with math.isclose()
• Name things according to PEP 8, with names that state meaning and unit

Check your understanding

1. Why test a program with known answers before using it on real data?
2. Which command creates a virtual environment named .venv?
3. What does type(4.0).__name__ return?
4. How many m/s is 72 km/h?
5. Under PEP 8, how should a constant for the Earth’s radius be named?