Figure.savefig: Add type hints and improve docstrings

pygmt/figure.py

@@ -4,7 +4,7 @@
 
 import base64
 import os
-from pathlib import Path
+from pathlib import Path, PurePath
 from tempfile import TemporaryDirectory
 
 try:
@@ -253,12 +253,12 @@
 
     def savefig(  # noqa: PLR0912
         self,
-        fname,
-        transparent=False,
-        crop=True,
-        anti_alias=True,
-        show=False,
-        worldfile=False,
+        fname: str | PurePath,
+        transparent: bool = False,
+        crop: bool = True,
+        anti_alias: bool = True,
+        show: bool = False,
+        worldfile: bool = False,
         **kwargs,
     ):
         """
@@ -280,45 +280,39 @@
         - EPS (``.eps``)
         - PDF (``.pdf``)
 
-        Beside the above formats, you can also save the figure to a KML file
-        (``.kml``), with a companion PNG file generated automatically. The KML
-        file can be viewed in Google Earth.
+        Besides the above formats, you can also save the figure to a KML file
+        (``.kml``), with a companion PNG file generated automatically. The KML file can
+        be viewed in Google Earth.
 
-        You can pass in any keyword arguments that
-        :meth:`pygmt.Figure.psconvert` accepts.
+        You can pass in any keyword arguments that :meth:`pygmt.Figure.psconvert`
+        accepts.
 
         Parameters
         ----------
-        fname : str
-            The desired figure file name, including the extension. See the list
-            of supported formats and their extensions above.
-        transparent : bool
-            If ``True``, will use a transparent background for the figure.
-            Only valid for PNG format.
-        crop : bool
-            If ``True``, will crop the figure canvas (page) to the plot area.
-        anti_alias: bool
-            If ``True``, will use anti-aliasing when creating raster images.
-            More specifically, it passes the arguments ``"t2"`` and ``"g2"``
-            to the ``anti_aliasing`` parameter of
-            :meth:`pygmt.Figure.psconvert`. Ignored if creating vector images.
-        show: bool
-            If ``True``, will open the figure in an external viewer.
-        worldfile : bool
-            If ``True``, will create a companion
-            `world file <https://en.wikipedia.org/wiki/World_file>`__ for the
-            figure. The world file will have the same name as the figure file
-            but with different extension (e.g. tfw for tif). See
-            https://en.wikipedia.org/wiki/World_file#Filename_extension
-            for the convention of world file extensions. This parameter only
-            works for raster image formats (except GeoTIFF).
-        dpi : int
-            Set raster resolution in dpi [Default is ``720`` for PDF, ``300``
-            for others].
+        fname
+            The desired figure file name, including the extension. See the list of
+            supported formats and their extensions above.
+        transparent
+            Use a transparent background for the figure. Only valid for PNG format.
+        crop
+            Crop the figure canvas (page) to the plot area.
+        anti_alias
+            Use anti-aliasing when creating raster images. Ignored if creating vector
+            images. More specifically, it passes the arguments ``"t2"`` and ``"g2"`` to
+            the ``anti_aliasing`` parameter of :meth:`pygmt.Figure.psconvert`.
+        show
+            Display the figure in an external viewer.
+        worldfile
+            Create a companion `world file <https://en.wikipedia.org/wiki/World_file>`__
+            for the figure. The world file will have the same name as the figure file
+            but with different extension (e.g., ``.tfw`` for ``.tif``). See
+            https://en.wikipedia.org/wiki/World_file#Filename_extension for the
+            convention of world file extensions. This parameter only works for raster
+            image formats (except GeoTIFF).
         **kwargs : dict
-            Additional keyword arguments passed to
-            :meth:`pygmt.Figure.psconvert`. Valid parameters are ``gs_path``,
-            ``gs_option``, ``resize``, ``bb_style``, and ``verbose``.
+            Additional keyword arguments passed to :meth:`pygmt.Figure.psconvert`. Valid
+            parameters are ``dpi``, ``gs_path``, ``gs_option``, ``resize``,
+            ``bb_style``, and ``verbose``.
         """
         # All supported formats
         fmts = {
@@ -382,7 +376,7 @@
             fname.with_suffix("." + ext).rename(fname)
 
         if show:
-            launch_external_viewer(fname)
+            launch_external_viewer(str(fname))
 
     def show(self, dpi=300, width=500, method=None, waiting=0.5, **kwargs):
         """