Python: Add progress argument to exact_extract

python/src/exactextract/exact_extract.py

@@ -251,6 +251,7 @@ def exact_extract(
     max_cells_in_memory: int = 30000000,
     output: str = "geojson",
     output_options: Optional[Mapping] = None,
+    progress=False,
 ):
     """Calculate zonal statistics
 
@@ -297,7 +298,9 @@ def exact_extract(
                            which may be significant for operations with large result sizes
                            such as ``cell_id``, ``values``, etc.
        output_options: an optional dictionary of options passed to the :py:class:`writer.JSONWriter`, :py:class:`writer.PandasWriter`, or :py:class:`writer.GDALWriter`.
-
+       progress: if `True`, a progress bar will be displayed. Alternatively, a
+                 function may be provided that will be called with the completion fraction
+                 and a status message.
     """
     rast = prep_raster(rast)
     weights = prep_raster(weights, name_root="weight")
@@ -317,8 +320,35 @@ def exact_extract(
     if include_geom:
         processor.add_geom()
     processor.set_max_cells_in_memory(max_cells_in_memory)
-    processor.process()
 
+    if progress:
+        processor.show_progress(True)
+
+        if callable(progress):
+            processor.set_progress_fn(progress)
+        elif progress is True:
+            try:
+                import tqdm
+
+                bar = tqdm.tqdm(total=100)
+
+                def status(frac, message):
+                    pct = frac * 100
+                    bar.update(pct - bar.n)
+                    bar.set_description(message)
+                    if pct == 100:
+                        bar.close()
+
+            except ImportError:
+
+                def status(frac, message):
+                    print(f"[{frac*100:0.1f}%] {message}")
+
+            processor.set_progress_fn(status)
+        else:
+            raise ValueError("progress should be True or a function")
+
+    processor.process()
     writer.finish()
 
     return writer.features()

python/tests/test_exact_extract.py

@@ -1170,3 +1170,13 @@ def test_explicit_operation():
     results = exact_extract(None, square, op)
 
     assert results[0]["properties"]["my_op"] == 4.0
+
+
+def test_progress():
+
+    rast = NumPyRasterSource(np.arange(9).reshape(3, 3))
+    square = make_rect(0.5, 0.5, 2.5, 2.5)
+
+    squares = [square] * 10
+
+    exact_extract(rast, squares, "count", progress=True)