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| |
| # I/O Read |
| |
| When you create a pipeline, you often need to read data from some external source, such as a file |
| or a database. Likewise, you may want your pipeline to output its result data to an external |
| storage system. Beam provides read and write transforms for a number of common data storage types. |
| |
| Package [textio](https://godoc.org/github.com/apache/beam/sdks/go/pkg/beam/io/textio) |
| contains transforms for reading and writing text files. |
| [textio.Read](https://godoc.org/github.com/apache/beam/sdks/go/pkg/beam/io/textio#Read) reads a set of files and |
| returns the lines as a PCollection<string>. |
| |
| **Kata:** Read the 'countries.txt' file and convert each country name into uppercase. |
| |
| <div class="hint"> |
| Use the <a href="https://godoc.org/github.com/apache/beam/sdks/go/pkg/beam/io/textio#Read"> |
| textio.Read</a> method. |
| </div> |
| |
| <div class="hint"> |
| Refer to the Beam Programming Guide |
| <a href="https://beam.apache.org/documentation/programming-guide/#pipeline-io-reading-data"> |
| "Reading input data"</a> section for more information. |
| </div> |
