feat: add GeoSeries.from_wkt() and GeoSeries.to_wkt() (#1401)

* feat: add GeoSeries.from_wkt() and GeoSeries.to_wkt()

* update paramas and test

* fix to_wkt test by removing whitespace

* fix docstrings missing import

* fix to_wkt test

* remove comment from docstrings

* Apply suggestions from code review

---------

Co-authored-by: Tim Sweña (Swast) <[email protected]>

Author: arwas11

bigframes/bigquery/_operations/geo.py

@@ -24,7 +24,7 @@
 """
 
 
-def st_area(self) -> bigframes.series.Series:
+def st_area(series: bigframes.series.Series) -> bigframes.series.Series:
     """
     Returns the area in square meters covered by the polygons in the input
     GEOGRAPHY.
@@ -35,7 +35,7 @@ def st_area(self) -> bigframes.series.Series:
 
 
     ..note::
-        BigQuery's Geography functions, like `st_area`, interpet the geomtry
+        BigQuery's Geography functions, like `st_area`, interpret the geometry
         data type as a point set on the Earth's surface. A point set is a set
         of points, lines, and polygons on the WGS84 reference spheroid, with
         geodesic edges. See: https://cloud.google.com/bigquery/docs/geospatial-data
@@ -88,6 +88,6 @@ def st_area(self) -> bigframes.series.Series:
       bigframes.pandas.Series:
           Series of float representing the areas.
     """
-    series = self._apply_unary_op(ops.geo_area_op)
+    series = series._apply_unary_op(ops.geo_area_op)
     series.name = None
     return series

bigframes/core/compile/scalar_op_compiler.py

@@ -1013,6 +1013,18 @@ def geo_area_op_impl(x: ibis_types.Value):
     return typing.cast(ibis_types.GeoSpatialValue, x).area()
 
 
+@scalar_op_compiler.register_unary_op(ops.geo_st_astext_op)
+def geo_st_astext_op_impl(x: ibis_types.Value):
+    return typing.cast(ibis_types.GeoSpatialValue, x).as_text()
+
+
+@scalar_op_compiler.register_unary_op(ops.geo_st_geogfromtext_op)
+def geo_st_geogfromtext_op_impl(x: ibis_types.Value):
+    # Ibis doesn't seem to provide a dedicated method to cast from string to geography,
+    # so we use a BigQuery scalar function, st_geogfromtext(), directly.
+    return st_geogfromtext(x)
+
+
 @scalar_op_compiler.register_binary_op(ops.geo_st_geogpoint_op, pass_op=False)
 def geo_st_geogpoint_op_impl(x: ibis_types.Value, y: ibis_types.Value):
     return typing.cast(ibis_types.NumericValue, x).point(
@@ -1930,6 +1942,11 @@ def _ibis_num(number: float):
     return typing.cast(ibis_types.NumericValue, ibis_types.literal(number))
 
 
+@ibis_udf.scalar.builtin
+def st_geogfromtext(a: str) -> ibis_dtypes.geography:  # type: ignore
+    """Convert string to geography."""
+
+
 @ibis_udf.scalar.builtin
 def timestamp(a: str) -> ibis_dtypes.timestamp:  # type: ignore
     """Convert string to timestamp."""

bigframes/geopandas/geoseries.py

@@ -17,6 +17,7 @@
 import bigframes_vendored.geopandas.geoseries as vendored_geoseries
 import geopandas.array  # type: ignore
 
+import bigframes.geopandas
 import bigframes.operations as ops
 import bigframes.series
 
@@ -67,6 +68,12 @@ def area(self, crs=None) -> bigframes.series.Series:  # type: ignore
             f"GeoSeries.area is not supported. Use bigframes.bigquery.st_area(series), instead. {constants.FEEDBACK_LINK}"
         )
 
+    @classmethod
+    def from_wkt(cls, data, index=None) -> GeoSeries:
+        series = bigframes.series.Series(data, index=index)
+
+        return cls(series._apply_unary_op(ops.geo_st_geogfromtext_op))
+
     @classmethod
     def from_xy(cls, x, y, index=None, session=None, **kwargs) -> GeoSeries:
         # TODO: if either x or y is local and the other is remote. Use the
@@ -75,3 +82,8 @@ def from_xy(cls, x, y, index=None, session=None, **kwargs) -> GeoSeries:
         series_y = bigframes.series.Series(y, index=index, session=session, **kwargs)
 
         return cls(series_x._apply_binary_op(series_y, ops.geo_st_geogpoint_op))
+
+    def to_wkt(self: GeoSeries) -> bigframes.series.Series:
+        series = self._apply_unary_op(ops.geo_st_astext_op)
+        series.name = None
+        return series

bigframes/operations/__init__.py

@@ -87,6 +87,8 @@
 )
 from bigframes.operations.geo_ops import (
     geo_area_op,
+    geo_st_astext_op,
+    geo_st_geogfromtext_op,
     geo_st_geogpoint_op,
     geo_x_op,
     geo_y_op,
@@ -353,10 +355,12 @@
     "euclidean_distance_op",
     "manhattan_distance_op",
     # Geo ops
-    "geo_x_op",
-    "geo_y_op",
     "geo_area_op",
+    "geo_st_astext_op",
+    "geo_st_geogfromtext_op",
     "geo_st_geogpoint_op",
+    "geo_x_op",
+    "geo_y_op",
     # Numpy ops mapping
     "NUMPY_TO_BINOP",
     "NUMPY_TO_OP",

bigframes/operations/geo_ops.py

@@ -37,6 +37,22 @@
     ),
 )
 
+
+geo_st_astext_op = base_ops.create_unary_op(
+    name="geo_st_astext",
+    type_signature=op_typing.FixedOutputType(
+        dtypes.is_geo_like, dtypes.STRING_DTYPE, description="geo-like"
+    ),
+)
+
+
+geo_st_geogfromtext_op = base_ops.create_unary_op(
+    name="geo_st_geogfromtext",
+    type_signature=op_typing.FixedOutputType(
+        dtypes.is_string_like, dtypes.GEO_DTYPE, description="string-like"
+    ),
+)
+
 geo_st_geogpoint_op = base_ops.create_binary_op(
     name="geo_st_geogpoint", type_signature=op_typing.BinaryNumericGeo()
 )