Figure.show: Raise ImportError instead of GMTError if IPython is not installed but required (#3580)

Author: seisman

pygmt/figure.py

@@ -17,7 +17,7 @@
 
 import numpy as np
 from pygmt.clib import Session
-from pygmt.exceptions import GMTError, GMTInvalidInput
+from pygmt.exceptions import GMTInvalidInput
 from pygmt.helpers import launch_external_viewer, unique_name
 
 
@@ -331,11 +331,12 @@ def show(
         match method:
             case "notebook":
                 if not _HAS_IPYTHON:
-                    raise GMTError(
+                    msg = (
                         "Notebook display is selected, but IPython is not available. "
                         "Make sure you have IPython installed, "
                         "or run the script in a Jupyter notebook."
                     )
+                    raise ImportError(msg)
                 png = self._preview(
                     fmt="png", dpi=dpi, anti_alias=True, as_bytes=True, **kwargs
                 )
@@ -344,14 +345,15 @@ def show(
                 pdf = self._preview(
                     fmt="pdf", dpi=dpi, anti_alias=False, as_bytes=False, **kwargs
                 )
-                launch_external_viewer(pdf, waiting=waiting)  # type: ignore[arg-type]
+                launch_external_viewer(pdf, waiting=waiting)
             case "none":
                 pass  # Do nothing
             case _:
-                raise GMTInvalidInput(
-                    f"Invalid display method '{method}'. Valid values are 'external', "
-                    "'notebook', 'none' or None."
+                msg = (
+                    f"Invalid display method '{method}'. "
+                    "Valid values are 'external', 'notebook', 'none' or None."
                 )
+                raise GMTInvalidInput(msg)
 
     def _preview(self, fmt: str, dpi: int, as_bytes: bool = False, **kwargs):
         """
@@ -400,7 +402,7 @@ def _repr_html_(self):
         html = '<img src="data:image/png;base64,{image}" width="{width}px">'
         return html.format(image=base64_png.decode("utf-8"), width=500)
 
-    from pygmt.src import (  # type: ignore [misc]
+    from pygmt.src import (  # type: ignore[misc]
         basemap,
         coast,
         colorbar,

pygmt/tests/test_figure.py

@@ -12,7 +12,7 @@
 import numpy.testing as npt
 import pytest
 from pygmt import Figure, set_display
-from pygmt.exceptions import GMTError, GMTInvalidInput
+from pygmt.exceptions import GMTInvalidInput
 from pygmt.figure import SHOW_CONFIG, _get_default_display_method
 from pygmt.helpers import GMTTempFile
 
@@ -321,7 +321,7 @@ def test_figure_show_notebook_error_without_ipython():
     """
     fig = Figure()
     fig.basemap(region=[0, 1, 2, 3], frame=True)
-    with pytest.raises(GMTError):
+    with pytest.raises(ImportError):
         fig.show(method="notebook")
 
 
@@ -361,7 +361,7 @@ def test_set_display(self):
                 assert mock_viewer.call_count == 0
                 assert mock_display.call_count == 1
         else:
-            with pytest.raises(GMTError):
+            with pytest.raises(ImportError):
                 fig.show()
 
         # Test the "external" display method