main.py

import os

def define_env(env):
    """
    This is the hook for defining variables, macros and filters

    - variables: the dictionary that contains the environment variables
    - macro: a decorator function, to declare a macro.
    """


    @env.macro
    def include_file(filename, start_line=0, end_line=None):
        """
        Include a file, optionally indicating start_line and end_line
        (start counting from 0)
        The path is relative to the top directory of the documentation
        project.
        """
        full_filename = os.path.join(env.project_dir, filename)
        with open(full_filename, 'r') as f:
            lines = f.readlines()
        line_range = lines[start_line:end_line]
        return ''.join(line_range)