Packages

Learn about packages in MicroPython and how they help organize and reuse code.

Packages

In MicroPython, a package is a collection of modules that are organized in a directory structure. Packages help in organizing code and making it reusable. A package can contain sub-packages, modules, and other resources.

What is a Package?

A package is a directory containing a special file named __init__.py. This file can be empty or contain initialization code for the package. The presence of the __init__.py file indicates to Python that the directory should be treated as a package.

Structure of a Package

Here’s an example of a simple package structure:

my_package/
    __init__.py
    module1.py
    module2.py
    sub_package/
        __init__.py
        module3.py

In this example, my_package is a package that contains two modules (module1.py and module2.py) and a sub-package (sub_package) which itself contains an __init__.py file and a module (module3.py).

Creating and Using Packages

Step 1: Create a Package

Create a directory for your package. Inside this directory, create an __init__.py file and the modules you need. For example, create the following structure:

my_robot_package/
    __init__.py
    motors.py
    sensors.py

Step 2: Add Code to Modules

Add the following code to motors.py:

# motors.py

class Motor:
    def __init__(self, power):
        self.power = power

    def move(self, direction):
        print(f"Moving {direction} with power {self.power}")

And add the following code to sensors.py:

# sensors.py

class Sensor:
    def __init__(self, type):
        self.type = type

    def read_value(self):
        # Simulate reading a sensor value
        return 42

Step 3: Use the Package in Your Main Program

Create a main program file and import the package modules:

# main.py

from my_robot_package.motors import Motor
from my_robot_package.sensors import Sensor

motor = Motor(100)
motor.move("forward")

sensor = Sensor("Ultrasonic")
print(sensor.read_value())

In this example, you create a package my_robot_package with two modules: motors.py and sensors.py. The main program imports and uses the classes from these modules.

Benefits of Using Packages

• Code Organization: Packages help you organize your code into a structured directory, making it easier to navigate and manage.
• Reusability: Packages allow you to reuse code across different projects, reducing duplication and effort.
• Namespace Management: Packages provide a way to manage namespaces, avoiding conflicts between module names in different packages.

Best Practices for Using Packages

1. Meaningful Names: Use meaningful names for your packages and modules to make your code more readable.
2. Keep __init__.py Minimal: Keep the __init__.py file minimal to avoid unnecessary complexity.
3. Document Your Code: Add documentation to your packages and modules to help other developers understand and use your code.

Summary

Packages in MicroPython are directories containing modules and an __init__.py file. They help organize and reuse code by grouping related modules together. By creating and using packages, you can improve the structure, maintainability, and reusability of your code.

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