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File Geodatabase (FGDB) Format

Description​

ESRI File Geodatabase (.gdb) is a directory-based geospatial container for feature classes and tables. IterableData streams a selected layer through Fiona’s OpenFileGDB driver as GeoJSON-like Features. It is read-only and marked experimental. Aliases: gdb.

File Extensions​

  • .gdb — File Geodatabase directory (path to the .gdb folder)
  • Registry id: fgdb

Implementation Details​

Reading​

  • Requires a directory path (filename); streams/codecs are not supported
  • Lists layers with fiona.listlayers
  • Selects layer via layer or table in iterableargs
  • If exactly one layer exists, it is used automatically; multiple layers require an explicit selection
  • Yields {"type": "Feature", "id", "properties", "geometry"}
  • Streaming: features are not preloaded into a list

Writing​

Writing is not supported (WriteNotSupportedError).

Key Features​

  • Layer selection: layer / table
  • Streaming features: Fiona collection iteration
  • list_tables(): discover layer names

Usage​

from iterable import open_iterable

with open_iterable(
    "data.gdb",
    iterableargs={"format": "fgdb", "layer": "roads"},
) as source:
    for feature in source:
        print(feature["properties"], feature["geometry"])

Parameters​

ParameterTypeDefaultRequiredDescription
layerstrnoneConditionalLayer / feature class name
tablestrnoneConditionalAlias for layer

Required when the geodatabase contains more than one layer.

Installation​

pip install 'iterabledata[geospatial]'

Requires Fiona with OpenFileGDB support (GDAL).

Limitations​

  1. Read-only
  2. Directory path required (not a single flat file stream)
  3. Experimental maturity
  4. Requires Fiona/GDAL OpenFileGDB driver
  5. Multi-layer GDB without layer/table raises ValueError

Error Handling​

  • ImportError: missing fiona — install iterabledata[geospatial]
  • WriteNotSupportedError: any write mode or write() / write_bulk()
  • ReadError: stream/codec-only open without a path
  • ValueError: no layers, or multiple layers without selection
  • I/O / Fiona errors: missing path or unsupported driver