Input · Files

Parquet Reader

Reads a Parquet file and keeps the column types stored in it.

Also known as: Columnar, Arrow

How it works

The file is read through a drone with the types stored in it, so nothing is sniffed and nothing is re-typed. For a GeoParquet file the drone reports the coordinate reference system and the node carries it downstream, which is what the metric spatial nodes such as Buffer need. The path is typed in File path or bound to a column of the Loop's Current item, so a loop over a Directory reads one file per iteration.

Inputs and outputs

Settings

Example

A folder of monthly extracts, sales_2026-01.parquet onwards. Drop a Parquet Reader into a Loop fed by a Directory, bind File path to the item's path column, and the loop collects every month into one table.

More in Files

• CSV Reader — Reads a CSV or other delimited text file, such as a TSV. Column types are detected for you, and you can override them or read every column as text.
• Fixed-width Reader — Reads a text file whose columns sit at fixed character positions, such as a mainframe export or a legacy feed, slicing each line at the positions you set on a ruler over the file's first lines. Header row, start line, encoding and row limit work as in the CSV Reader.
• JSON Reader — Reads a .json, .jsonl or .ndjson file as a table. A JSON array of objects and one-object-per-line files are both detected automatically.
• Excel Reader — Reads one worksheet of an Excel workbook, the first sheet unless you pick another.
• Geo Reader — Reads a map file with its geometry: GeoJSON, Shapefile (also zipped), GeoPackage, GML, KML/KMZ, GPX, FlatGeobuf or MapInfo TAB. For a file with several layers, you pick which layer to read.
• XML Reader — Reads an XML file into a table. It finds the repeating record element for you, so each record becomes a row.
• SQLite Reader — Reads one table from a local SQLite database file (.sqlite, .sqlite3 or .db). You pick the table from the file's list of tables.
• Daedalus Table Reader — Reads a .ddtable file saved by Write Daedalus Table, in this project or another one. The column formats come back too, so everything prints as it did.