ENH: Add support for reading string lists

fiona/gdal.pxi

@@ -314,6 +314,7 @@ cdef extern from "ogr_api.h" nogil:
  double OGR_F_GetFieldAsDouble(OGRFeatureH feature, int n)
  int OGR_F_GetFieldAsInteger(OGRFeatureH feature, int n)
  const char *OGR_F_GetFieldAsString(OGRFeatureH feature, int n)
+ char **OGR_F_GetFieldAsStringList( OGRFeatureH feature, int n)
  int OGR_F_GetFieldCount(OGRFeatureH feature)
  OGRFieldDefnH OGR_F_GetFieldDefnRef(OGRFeatureH feature, int n)
  int OGR_F_GetFieldIndex(OGRFeatureH feature, const char *name)

fiona/ogrext.pyx

@@ -11,6 +11,7 @@ import os
 import warnings
 import math
 from collections import namedtuple, OrderedDict
+from typing import List
 from uuid import uuid4
 
 from six import integer_types, string_types, text_type
@@ -168,6 +169,8 @@ cdef class FeatureBuilder:
  cdef void *fdefn = NULL
  cdef int i
  cdef unsigned char *data = NULL
+ cdef char **string_list = NULL
+ cdef int string_list_index = 0
  cdef int l
  cdef int retval
  cdef int fieldsubtype
@@ -284,7 +287,20 @@ cdef class FeatureBuilder:
  elif fieldtype is bytes:
  data = OGR_F_GetFieldAsBinary(feature, i, &l)
  props[key] = data[:l]
-
+ elif fieldtype is List[str]:
+ string_list = OGR_F_GetFieldAsStringList(feature, i)
+ string_list_index = 0
+ props[key] = []
+ while string_list[string_list_index] != NULL:
+ val = string_list[string_list_index]
+ try:
+ val = val.decode(encoding)
+ except UnicodeDecodeError:
+ log.warning(
+ "Failed to decode %s using %s codec", val, encoding
+ )
+ props[key].append(val)
+ string_list_index += 1
  else:
  props[key] = None
 

fiona/schema.pyx

@@ -1,5 +1,7 @@
 from six import text_type
 
+from typing import List
+
 from fiona.errors import SchemaError
 from fiona.rfc3339 import FionaDateType, FionaDateTimeType, FionaTimeType
 
@@ -24,7 +26,7 @@ FIELD_TYPES = [
  'float', # OFTReal, Double Precision floating point
  None, # OFTRealList, List of doubles
  'str', # OFTString, String of UTF-8 chars
- None,  # OFTStringList, Array of strings
+ 'List[str]', # OFTStringList, Array of strings
  None, # OFTWideString, deprecated
  None, # OFTWideStringList, deprecated
  'bytes', # OFTBinary, Raw Binary data
@@ -45,7 +47,8 @@ FIELD_TYPES_MAP = {
  'datetime': FionaDateTimeType,
  'bytes': bytes,
  'int64': int,
- 'int': int
+ 'int': int,
+ 'List[str]': List[str],
 }
 
 FIELD_TYPES_MAP_REV = dict([(v, k) for k, v in FIELD_TYPES_MAP.items()])

tests/test_schema.py

@@ -384,3 +384,34 @@ def test_schema_default_fields_wrong_type(tmpdir):
  driver="GPX",
  schema=schema) as c:
  pass
+
+
+def test_schema_string_list(tmp_path):
+ output_file = tmp_path / "fio_test.geojson"
+ schema = {
+ "properties": {
+ "time_range": "str",
+ },
+ "geometry": "Point",
+}
+ with fiona.open(
+ output_file, "w", driver="GeoJSON", schema=schema, crs="EPSG:4326"
+ ) as fds:
+ fds.writerecords(
+ [
+ {
+ "id": 1,
+ "geometry": {"type": "Point", "coordinates": [0.0, 0.0]},
+ "properties": {
+ "time_range": '["2020-01-01", "2020-01-02"]',
+ },
+ }
+ ]
+ )
+
+ with fiona.open(output_file) as fds:
+ assert fds.schema["properties"] == {"time_range": "List[str]"}
+ layers = list(fds)
+ assert layers[0]["properties"] == {
+ "time_range": ["2020-01-01", "2020-01-02"]
+ }