Python on Android: how to write and run code from a smartphone

Installing Python in Termux: step-by-step guide

Termux is a Swiss knife for a developer on AndroidTo set it up to work. from Python, follow these steps:

1. Install Termux from F-Droid (the version from Google Play is outdated and not updated After installation, open the application and wait for initialization). repositories.

2. Update the packages with the command:

   pkg update && pkg upgrade

   This will take a few minutes depending on the Internet speed.

3. Install Python and pip:

   pkg install python

   To check the version, enter:

   python --version

   You should see something like Python 3.11.6.

4. Install a text editor (for example, nano or vim):

   pkg install nano

Now you can create and run scripts. For example, create a file hello.py:

nano hello.py

Insert code:

print("Hello from Termux!")
import platform
print(f"Python version: {platform.python_version()}")
print(f"OS: {platform.system()}")

Save (Ctrl+O → Enter → Ctrl+X) and run:

python hello.py

⚠️ Attention: By default, Termux stores files in its isolated folder. To access them from other applications (for example, a file manager), use the command:

termux-setup-storage

This will create a symbolic link to the folder /storage/emulated/0 (internal memory of the device).

Working with libraries: how to install NumPy, Pandas and others

In Termux installing libraries is no different from Linux:

pip install numpy pandas matplotlib

But there are nuances:

• 🐍 Compatibility: Not all packages support ARM architecture (especially those that require compilation, for example scikit-learn). Before installation, check the availability of wheel files for aarch64 on PyPI.
• 📦 Alternatives: For heavy libraries (for example, TensorFlow) use lightweight versions:

  pip install tensorflow-cpu

  or specialized assemblies for mobile devices:

  pip install tflite-runtime

• 🔄 Virtual environment: To avoid conflicts, create isolated environments:

  python -m venv myenv
  source myenv/bin/activate

In Pydroid 3 i QPython the process is simplified: libraries are installed via a graphical interface. data-i="149">Open menu Pydroid:

1. Open menu Pip.
2. Enter the package name (for example, requests).
3. Click Install.

But there is a limitation: not all packages are available due to the features of the Androidassembly.

pip install numpy==1.23.5

The list of compatible versions can be found on the package page in PyPI, in the "Download" section files".-->

Synchronizing projects: Git, cloud storage and SSH

Working with code on a smartphone is convenient only if it is reliably synchronized. Here are the main methods:

• 🔗 Git: In Termux install git and configure access to the repositories:

  pkg install git
  git config --global user.name "Your name"
  git config --global user.email "your@email.com"

  For authentication, use SSH keys or tokens (for GitHub, GitLab).

• ☁️ Cloud storage: Applications like Termux can mount Google Drive or Dropbox via rclone:

  pkg install rclone
  rclone config

  Follow the instructions to link your account.

• 📱 Local network: It is convenient to use ADB (Android Debug Bridge) to transfer files between PC and phone or FTP server in Termux:

  pkg install openssh
  sshd

  Connect using IPphone address (you can find it out with the command ifconfig).

For Pydroid 3 synchronization is simplified: the application supports export/import of projects via Google Drive or local files. However, for team work it is better to use Termux + Git - this gives full control over versions.

⚠️ Attention: When working with SSH on public Wi-Fi networks, use VPN or configure fail2ban on the server. Androiddevices often become targets for brute force attacks due to open ports.

Practical examples: what can be programmed in Python directly from your phone

Python on Android is not just educational tasks. Here are some real projects that can be implemented:

• 📊 Data analysis: Collect statistics from smartphone sensors (accelerometer, gyroscope) via SL4A (Scripting Layer for Android) and visualize it using Matplotlib. Example code for obtaining accelerometer data:

  import android
  droid = android.Android()
  sensors = droid.getLastKnownLocation().result
  print(f"Accelerometer: {sensors['acceleration']}")

• 🤖 Automation: Write a script to automatically respond to SMS or manage notifications. The library plyer allows you to work with phone functions:

  from plyer import notification
  notification.notify(title="Reminder", message="Time to take a break!")

• 🎮 Games: Using Pygame (available in Termux) you can create simple 2D games. For rendering, it is used SDL2, which supports touch input.
• 🌐 Web scraping: Parse data from sites using BeautifulSoup or Selenium (installation required firefox in Termux).

Integration with Android APIis especially interesting. For example, you can write a script that:

1. Reads GPScoordinates.
2. Sends them to the server or saves them in SQLite.
3. Builds a route on the map using folium.

import android
droid = android.Android()
location = droid.getLastKnownLocation().result
if location:
lat = location['gps']['latitude']
lon = location['gps']['longitude']
print(f"Your coordinates: {lat}, {lon}")
else:
print("GPS is disabled or data is unavailable")

Performance optimization: how to speed up code execution

Python on Android runs slower than on a PC, but there are ways to speed it up execution:

import numpy as np
a = np.array([1, 2, 3])
b = a * 2 # Faster than a for loop

pip install numpy --no-deps

def read_large_file(f):
for line in f:
yield line # Does not load the entire file into memory

pip install /path/to/package.whl

For truly resource-intensive tasks (for example, training neural networks) consider the options:

• 🖥️ Remote server: Run the code on Google Colab or your own VPS, and from your phone connect via SSH.
• ☁️ Cloud IDEs: Replit or GitHub Codespaces allow you to write code on the phone, but execute it on your servers.

Solving common errors and problems

When working with Python on Android users encounter typical errors. Here are the most common ones and how to fix them:

• 🐞 "ModuleNotFoundError": The library is installed but not located. Reason: Termux uses its own file system. Solution:

  LD_LIBRARY_PATH=/data/data/com.termux/files/usr/lib python -c "import numpy"

  Or install the package systemically:

  pkg install python-numpy

• 🔌 "Permission denied": Android blocks access to some folders. Use:

  termux-setup-storage

  and work in /storage/emulated/0.

• 📱 The keyboard is in the way encode: Install Hacker's Keyboard from Google Play - it supports Ctrl, Alt and arrows.
• 🔋 The script is interrupted when the screen is locked: Disable battery optimization for Termux in settings Android or use:

  termux-wake-lock

  so that the screen does not go dark.

If Pydroid 3 or QPython crashes when running the script, try:

1. Clear the application cache.
2. Reduce the project size (split into smaller files).
3. Disable background processes (especially if the phone has low RAM).

⚠️ Attention: On some devices (for example, Xiaomi or Huawei) Android aggressively closes background processes, including Termux. Add the application to the list of exceptions in settings batteries.

FAQ: answers to frequently asked questions

pip install django flask

setxkbmap us # for English layout

pip freeze > requirements.txt

pip install -r requirements.txt