How to automatically generate documentation for a custom Python module?

In Python, there are many tools for generating code documentation, one of which is very powerful and easy to use is the pydoc library. pydoc can automatically generate readable and beautiful documentation without any additional configuration. This article will introduce the usage of the pydoc library and provide corresponding code, output and analysis.

Introduction

pydoc is a module in the Python standard library used to generate documentation for Python code. It automatically generates documentation based on docstrings in your code and provides a user-friendly interface to view and browse documentation. pydoc supports a variety of document formats, including plain text, HTML, and Man pages.

Usage example

Let's demonstrate the usage of pydoc through a simple example. Suppose we have a file called calculator.py that contains a class Calculator that performs basic mathematical operations. Here is the code for this example class:

class Calculator:
   """
  A simple calculator class.

  Attributes:
      name (str): The name of the calculator.

  Methods:
      add(a, b): Add two numbers.
      subtract(a, b): Subtract one number from another.
      multiply(a, b): Multiply two numbers.
      divide(a, b): Divide one number by another.
  """

   def __init__(self, name):
       """
      Initialize the calculator object.

      Args:
          name (str): The name of the calculator.
      """
       self.name = name

   def add(self, a, b):
       """
      Add two numbers.

      Args:
          a (int or float): The first number.
          b (int or float): The second number.

      Returns:
          The sum of the two numbers.
      """
       return a + b

   def subtract(self, a, b):
       """
      Subtract one number from another.

      Args:
          a (int or float): The number to subtract from.
          b (int or float): The number to subtract.

      Returns:
          The difference between the two numbers.
      """
       return a - b

   def multiply(self, a, b):
       """
      Multiply two numbers.

      Args:
          a (int or float): The first number.
          b (int or float): The second number.

      Returns:
          The product of the two numbers.
      """
       return a * b

   def divide(self, a, b):
       """
      Divide one number by another.

      Args:
          a (int or float): The number to divide.
          b (int or float): The number to divide by.

      Returns:
          The quotient of the two numbers.
      """
       if b == 0:
           raise ValueError("Division by zero is not allowed.")
       return a / b
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To generate documentation for this class, we can run the following command on the command line:

python -m pydoc calculator
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After running this command, pydoc will parse the calculator.py file and generate the corresponding documentation. The following is an example of the generated documentation:

Help on module calculator:

NAME
  calculator - A simple calculator class.

DESCRIPTION
  Attributes:
      name (str): The name of the calculator.

  Methods:
      add(a, b): Add two numbers.
      subtract(a, b): Subtract one number from another.
      multiply(a, b): Multiply two numbers.
      divide(a, b): Divide one number by another.

CLASSES
  builtins.object
      Calculator

  class Calculator(builtins.object)
    | Calculator(name)
    |  
    | A simple calculator class.
    |  
    | Methods defined here:
    |  
    | __init__(self, name)
    |     Initialize the calculator object.
    |  
    | add(self, a, b)
    |     Add two numbers.
    |  
    | divide(self, a, b)
    |     Divide one number by another.
    |  
    | multiply(self, a, b)
    |     Multiply two numbers.
    |  
    | subtract(self, a, b)
    |     Subtract one number from another.

DATA
  __all__ = ['Calculator']

FILE
  /path/to/calculator.py
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From the above output, we can see that pydoc has successfully generated the documentation. The output document includes module description, class description, method description, and parameter and return value descriptions. In addition, the path to the file and the module hierarchy are included.

parse

Let us parse the output of the above example to better understand the generated documentation.

• Help on module calculator:: This is module-level help information, showing the name of the module.
• NAME: This is the name of the module, followed by a description of the module.
• DESCRIPTION: This is a description of the module, which provides general information about the module, including a summary of properties and methods.
• CLASSES: This is a list containing the classes defined in the module.
• class Calculator(builtins.object): This is the definition of the class, which contains the name of the class and the base class. In this example, the Calculator class inherits from the object class.
• Methods defined here: This is the list of methods defined in the class.
• __init__(self, name): This is the constructor of Calculator class, it accepts one parameter name.
• add(self, a, b): This is the add method of Calculator class, it accepts two parameters a and b.
• divide(self, a, b): This is the divide method of Calculator class which accepts two parameters a and b.
• multiply(self, a, b): This is the multiply method of Calculator class which accepts two parameters a and b.
• subtract(self, a, b): This is the subtract method of Calculator class which accepts two parameters a and b.
• DATA: This is other data defined in the module.
• FILE: This is the path to the file indicating the source file from which the document was generated.

From the generated documentation, we can clearly understand the structure of modules, classes, and methods. Each method has corresponding descriptions of parameters and return values, which makes the documentation easy to read and understand.

in conclusion

pydoc is a powerful and easy-to-use tool for generating documentation of Python code. By parsing docstrings in your code, pydoc can automatically generate clear, readable documentation and provide a user-friendly interface for viewing and browsing the documentation. This article provides a simple example of how to use pydoc to generate documentation and parses the structure and content of the generated documentation.

Using pydoc can help developers better organize and present their code documentation, improving code readability and maintainability. By adding appropriate docstrings to the code and using pydoc to generate documentation, developers can more easily share the code with others and make it easier to understand and use.

I hope this article will help you understand and use pydoc!