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Create a New Readerยค

When adding a new Reader to the repository the following steps should be performed.

uv is used as the package and project manager for msl-io development, it is recommended to install it.

Note

If you do not want to contribute your new Reader to the repository then you only need to write the code shown in Step 2 to use your Reader in your own software. Once you import your module in your code, your Reader will be registered and it will be used to read your data files.

  1. Create a fork of the repository.

  2. Create a new Reader by following this template. Save it in the src/msl/io/readers folder.

    from __future__ import annotations
    
    # It's a good idea to provide type annotations in your code
    from typing import TYPE_CHECKING
    
    # Import the necessary msl-io object to subclass
    from msl.io import Reader
    
    if TYPE_CHECKING:
        from typing import Any
    
        from msl.io.types import ReadLike
    
    
    # Sub-classing Reader will tell msl-io that your MyReader exists
    class MyReader(Reader):
        """Name your class to be whatever you want, i.e., change MyReader."""
    
        @staticmethod
        def can_read(file: ReadLike | str, **kwargs: Any) -> bool:
            """This method answers the following question:
    
            Given a file-like object (e.g., a file stream or a buffered reader)
            or a file path, can your Reader read this file?
    
            You must perform all the necessary checks that *uniquely* answers
            this question. For example, checking that the file extension is a
            particular value may not be unique enough.
    
            The optional kwargs can be passed in via the msl.io.read() function.
    
            This method must return a boolean:
            True (can read) or False (cannot read)
            """
    
        def read(self, **kwargs: Any) -> None:
            """This method reads the data file(s).
    
            The optional kwargs can be passed in via the msl.io.read() function.
    
            Your Reader class is a Root object.
    
            The file to read is available at self.file
    
            To add metadata to Root use self.add_metadata()
    
            To create a Group in Root use self.create_group()
    
            To create a Dataset in Root use self.create_dataset()
    
            This method should return None.
            """
    
  3. Import your Reader in the src/msl/io/readers/__init__.py module. Follow what is done for the other Readers.

  4. Add an example data file to the tests/samples directory and add a test case to the tests directory. Make sure that your Reader is returned by calling the read function, using your example data file as the input, and that the information in the returned object is correct. Run the tests using uv run pytest.

  5. Lint uv run ruff check, format uv run ruff format and type check uv run basedpyright the code.

  6. Add the new Reader, alphabetically, to docs/readers/index.md. Follow what is done for the other Readers.

  7. Update CHANGELOG.md stating that you added this new Reader.

  8. Build the documentation uv run mkdocs serve and check that your Reader renders correctly.

  9. If running the tests pass and linting, formatting, type checking and building the documentation do not show errors/warnings then create a pull request.