learning/prompts/code-explanation/10_io_parquet.md

Prompt:
What does this code do?
```python
class ReadParquetOptions(PipelineOptions):

    @classmethod
    def _add_argparse_args(cls, parser):
      parser.add_argument(
          "--path",
          help="GCS path to parquet file")

  options = ReadParquetOptions()

with beam.Pipeline(options=options) as p:
    (p | "Read Parquet" >> ReadFromParquet(options.path)
       | Map(logging.info))
```

Response:
This code reads data from [Apache Parquet](https://parquet.apache.org/) files using the `ReadFromParquet` transform from the built-in [ParquetIO connector](https://beam.apache.org/releases/pydoc/current/apache_beam.io.parquetio.html).

```python
class ReadParquetOptions(PipelineOptions):

    @classmethod
    def _add_argparse_args(cls, parser):
      parser.add_argument(
          "--path",
          help="GCS path to parquet file")

  options = ReadParquetOptions()
```

The `ReadParquetOptions` class defines the command-line argument `--path`, which specifies the path to the Parquet file. To parse command-line arguments, this code uses [pipeline options](https://beam.apache.org/documentation/patterns/pipeline-options/).

```python
with beam.Pipeline(options=options) as p:
    (p | "Read Parquet" >> ReadFromParquet(options.path)
       | Map(logging.info))
```

The Apache Beam pipeline uses the `ReadParquetOptions` class to set the path to the Parquet file and the [`ReadFromParquet` transform](https://beam.apache.org/releases/pydoc/current/apache_beam.io.parquetio.html#apache_beam.io.parquetio.ReadFromParquet) to read data from the file.