Autocorrect output_type to 'file' if outfile parameter is set

Author: weiji14

pygmt/src/triangulate.py

@@ -2,6 +2,8 @@
 triangulate - Delaunay triangulation or Voronoi partitioning and gridding of
 Cartesian data.
 """
+import warnings
+
 import pandas as pd
 from pygmt.clib import Session
 from pygmt.exceptions import GMTInvalidInput
@@ -165,7 +167,7 @@ def regular_grid(  # pylint: disable=too-many-arguments,too-many-locals
         registration=None,
         skiprows=None,
         wrap=None,
-        **kwargs
+        **kwargs,
     ):
         """
         Delaunay triangle based gridding of Cartesian data.
@@ -257,7 +259,7 @@ def regular_grid(  # pylint: disable=too-many-arguments,too-many-locals
                 registration=registration,
                 skiprows=skiprows,
                 wrap=wrap,
-                **kwargs
+                **kwargs,
             )
 
     @staticmethod
@@ -281,7 +283,7 @@ def delaunay_triples(  # pylint: disable=too-many-arguments,too-many-locals
         incols=None,
         skiprows=None,
         wrap=None,
-        **kwargs
+        **kwargs,
     ):
         """
         Delaunay triangle based gridding of Cartesian data.
@@ -344,6 +346,15 @@ def delaunay_triples(  # pylint: disable=too-many-arguments,too-many-locals
                 "Must specify 'output_type' either as 'numpy', 'pandas' or 'file'."
             )
 
+        if isinstance(outfile, str) and output_type != "file":
+            msg = (
+                f"Changing 'output_type' from '{output_type}' to 'file' "
+                "since 'outfile' parameter is set. Please use output_type='file' "
+                "to silence this warning."
+            )
+            warnings.warn(message=msg, category=RuntimeWarning, stacklevel=2)
+            output_type = "file"
+
         # Return a pandas.DataFrame if ``outfile`` is not set
         with GMTTempFile(suffix=".txt") as tmpfile:
             if output_type != "file":
@@ -366,5 +377,5 @@ def delaunay_triples(  # pylint: disable=too-many-arguments,too-many-locals
                 incols=incols,
                 skiprows=skiprows,
                 wrap=wrap,
-                **kwargs
+                **kwargs,
             )

pygmt/tests/test_triangulate.py

@@ -107,6 +107,20 @@ def test_delaunay_triples_ndarray_output(dataframe, expected_dataframe):
     np.testing.assert_allclose(actual=output, desired=expected_dataframe.to_numpy())
 
 
+def test_delaunay_triples_outfile(dataframe, expected_dataframe):
+    """
+    Test triangulate.delaunay_triples with ``outfile``.
+    """
+    with GMTTempFile(suffix=".txt") as tmpfile:
+        with pytest.warns(RuntimeWarning) as record:
+            result = triangulate.delaunay_triples(data=dataframe, outfile=tmpfile.name)
+            assert len(record) == 1  # check that only one warning was raised
+        assert result is None  # return value is None
+        assert os.path.exists(path=tmpfile.name)
+        temp_df = pd.read_csv(filepath_or_buffer=tmpfile.name, sep="\t", header=None)
+        pd.testing.assert_frame_equal(left=temp_df, right=expected_dataframe)
+
+
 def test_delaunay_triples_invalid_format(dataframe):
     """
     Test that triangulate.delaunay_triples fails with incorrect format.