ServiceX_transformer Library
Library of common classes for building serviceX transformers.
Minimum Requiremnts
Works with Python version 2.7 and above
Download from PyPi
To use this library:
pip install servicex-transformerStandard Command Line Arguments
This library provides a subclass of ArgParse for standardizing commnand line arguments for all transformer implementations.
Available arguments are:
Transformed Result Output
Command line arguments determine a destination for the results as well as an output format.
- Object Store - Each transformed file is written as an object to an S3 compatible object store. The only currently supported output file format is parquet. The objects are stored in a bucket named after the transformation request ID.
Command Line Reference
| Option | Description | Default |
|---|---|---|
| --tree TREE | Root Tree to extract data from. Only valid for uproot transformer | Events |
| --path PATH | Path to single Root file to transform. Any file path readable by xrootd | |
| --limit LIMIT | Max number of events to process | |
| --result-destination DEST | Where to send the results: object-store, output-dir, volume | object-store |
| --output-dir | Local directory where the result will be written. Use this to run standalone without other serviceX infrastructure | None |
| --result-format | Binary format for the results: arrow, parquet, or root-file | arrow |
| --rabbit-uri URI | RabbitMQ Connection URI | host.docker.internal |
| --request-id GUID | ID associated with this transformation request. Used as RabbitMQ Topic Name as well as object-store bucket | servicex |
Running Tests
Validation of the code logic is performed using
pytest and
pytest-mock. Unit test fixtures are
in test directories inside each package.
The tests are instrumented with code coverage reporting via codecov. The travis job has a the codecov upload token set as an environment variable which is passed into the docker container so the report can be uploaded upon successful conclusion of the tests.
Coding Standards
To make it easier for multiple people to work on the codebase, we enforce PEP8
standards, verified by flake8. The community has found that the 80 character
limit is a bit awkward, so we have a local config setting the max_line_length
to 99.
