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FlatGeobuf Format

FlatGeobuf is a compact, cloud-friendly binary encoding for geospatial features. IterableData streams features through Fiona/GDAL and optionally filters with a bounding box. It is read-only in this release.

File Extensions​

  • .fgb — FlatGeobuf feature collections

Implementation Details​

Reading​

  • Opens a local filename (streams are not supported)
  • Optional bbox=(minx, miny, maxx, maxy) is passed to Fiona for spatial filtering
  • Each row is {**properties, "geometry": geojson-like geometry}

Writing​

Writing is not supported. Use GeoParquet or GeoJSONSeq for writeable geospatial pipelines. Attempting to write raises WriteNotSupportedError.

Key Features​

  • Streaming: one feature at a time
  • BBox selection: skip features outside a window
  • GDAL/Fiona: uses the installed FlatGeobuf driver

Usage​

from iterable import open_iterable

with open_iterable("features.fgb", iterableargs={"format": "flatgeobuf"}) as source:
    for row in source:
        print(row.get("name"), row["geometry"])

with open_iterable(
    "features.fgb",
    iterableargs={"format": "flatgeobuf", "bbox": (-10.0, 40.0, 0.0, 50.0)},
) as source:
    for row in source:
        print(row)

Parameters​

ParameterTypeDefaultRequiredDescription
bboxtuple of 4 floatsnoneNo(minx, miny, maxx, maxy) spatial filter

Error Handling​

  • ImportError: Missing Fiona/GDAL — install with pip install iterabledata[geospatial]
  • ValueError: Stream input or missing filename (FlatGeobuf requires a local filename)
  • WriteNotSupportedError: Writing FlatGeobuf is not supported
  • FileNotFoundError / Fiona errors: missing path, missing FlatGeobuf driver, or corrupt .fgb

See Troubleshooting for more help.

Installation​

pip install 'iterabledata[geospatial]'

Requires Fiona with GDAL FlatGeobuf support.

Limitations​

  1. Read-only
  2. Local filename required
  3. Requires Fiona/GDAL
  • GeoParquet — Parquet with geometry metadata (read and write)
  • GeoPackage — SQLite-based geospatial container
  • GeoJSONSeq — streaming JSON features