Input · 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.

Also known as: Import, read_csv, TSV

How it works

You give the node a file in Source: type a File path, or bind it to a column of the Loop's Current item so each iteration reads a different file. The column types are sniffed from the file; once the source has been previewed, Column types lists every column with its detected type, and you can override one with VARCHAR, BIGINT, DOUBLE, DATE, TIMESTAMP, TIME or BOOLEAN. Read all as text switches the sniffing off entirely, so every column arrives as text and you re-type what you need downstream with Cast Types. Send to AI as decides what an AI node downstream sees of this source: a few rows (5 by default, the first, a random pick or the last), a description you write, the schema, or nothing.

Inputs and outputs

Settings

Example

A customer export where postal codes lose their leading zeros. Keep the sniffed types and set the one column that matters:

More in Files

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