Files & formats

A spatial file is a container with opinions. Shapefile truncates field names at ten characters and cannot store a datetime. GeoJSON is always WGS 84, whatever you had. GeoPackage takes almost anything and puts it in one file. Reading is rarely the problem — GDAL handles around 200 vector formats behind one interface — so the work here is identification, selection, and knowing what a round trip costs.

The failures are mostly silent. A GeoPackage holding several layers hands you the first one. A shapefile copied without its .dbf opens with no attributes. A missing .prj gives you crs = None, which is not a bug but information that was lost at the moment somebody copied the file. None of these raise anything.

Below, the concepts cover what the formats are and what each one can carry, the how-to guides are one per format plus the conversions between them, and the fixes are the specific errors each format produces.

Learning paths run through this topic too — see the end of this page.