TYP: Add type hints to the Figure.tilemap method

pygmt/src/tilemap.py

@@ -2,17 +2,19 @@
 tilemap - Plot XYZ tile maps.
 """
 
-from __future__ import annotations
+from typing import Literal
 
 from pygmt.clib import Session
 from pygmt.datasets.tile_map import load_tile_map
 from pygmt.helpers import build_arg_string, fmt_docstring, kwargs_to_strings, use_alias
 
 try:
     import rioxarray  # noqa: F401
+    from xyzservices import TileProvider
 
     _HAS_RIOXARRAY = True
 except ImportError:
+    TileProvider = None
     _HAS_RIOXARRAY = False
 
 
@@ -34,86 +36,72 @@
 @kwargs_to_strings(c="sequence_comma", p="sequence")  # R="sequence",
 def tilemap(
     self,
-    region,
-    zoom="auto",
-    source=None,
-    lonlat=True,
-    wait=0,
-    max_retries=2,
+    region: list,
+    zoom: int | Literal["auto"] = "auto",
+    source: TileProvider | str | None = None,
+    lonlat: bool = True,
+    wait: int = 0,
+    max_retries: int = 2,
     zoom_adjust: int | None = None,
     **kwargs,
 ):
     r"""
     Plot an XYZ tile map.
 
     This method loads XYZ tile maps from a tile server or local file using
-    :func:`pygmt.datasets.load_tile_map` into a georeferenced form, and plots
-    the tiles as a basemap or overlay using :meth:`pygmt.Figure.grdimage`.
+    :func:`pygmt.datasets.load_tile_map` into a georeferenced form, and plots the tiles
+    as a basemap or overlay using :meth:`pygmt.Figure.grdimage`.
 
     **Note**: By default, standard web map tiles served in a Spherical Mercator
     (EPSG:3857) Cartesian format will be reprojected to a geographic coordinate
-    reference system (OGC:WGS84) and plotted with longitude/latitude bounds
-    when ``lonlat=True``. If reprojection is not desired, please set
-    ``lonlat=False`` and provide Spherical Mercator (EPSG:3857) coordinates to
-    the ``region`` parameter.
+    reference system (OGC:WGS84) and plotted with longitude/latitude bounds when
+    ``lonlat=True``. If reprojection is not desired, please set ``lonlat=False`` and
+    provide Spherical Mercator (EPSG:3857) coordinates to the ``region`` parameter.
 
     {aliases}
 
     Parameters
     ----------
-    region : list
-        The bounding box of the map in the form of a list [*xmin*, *xmax*,
-        *ymin*, *ymax*]. These coordinates should be in longitude/latitude if
-        ``lonlat=True`` or Spherical Mercator (EPSG:3857) if ``lonlat=False``.
-
-    zoom : int or str
-        Optional. Level of detail. Higher levels (e.g. ``22``) mean a zoom
-        level closer to the Earth's surface, with more tiles covering a smaller
-        geographical area and thus more detail. Lower levels (e.g. ``0``) mean
-        a zoom level further from the Earth's surface, with less tiles covering
-        a larger geographical area and thus less detail [Default is
-        ``"auto"`` to automatically determine the zoom level based on the
-        bounding box region extent].
+    region
+        The bounding box of the map in the form of a list [*xmin*, *xmax*, *ymin*,
+        *ymax*]. These coordinates should be in longitude/latitude if ``lonlat=True`` or
+        Spherical Mercator (EPSG:3857) if ``lonlat=False``.
+    zoom
+        Level of detail. Higher levels (e.g. ``22``) mean a zoom level closer to the
+        Earth's surface, with more tiles covering a smaller geographical area and thus
+        more detail. Lower levels (e.g. ``0``) mean a zoom level further from the
+        Earth's surface, with less tiles covering a larger geographical area and thus
+        less detail. Default is ``"auto"`` to automatically determine the zoom level
+        based on the bounding box region extent.
 
         .. note::
            The maximum possible zoom level may be smaller than ``22``, and depends on
            what is supported by the chosen web tile provider source.
-
-    source : xyzservices.TileProvider or str
-        Optional. The tile source: web tile provider or path to a local file.
-        Provide either:
-
-        - A web tile provider in the form of a
-          :class:`xyzservices.TileProvider` object. See
-          :doc:`Contextily providers <contextily:providers_deepdive>` for a
-          list of tile providers [Default is
-          ``xyzservices.providers.OpenStreetMap.HOT``, i.e. OpenStreetMap
-          Humanitarian web tiles].
-        - A web tile provider in the form of a URL. The placeholders for the
-          XYZ in the URL need to be {{x}}, {{y}}, {{z}}, respectively. E.g.
+    source
+        The tile source: web tile provider or path to a local file. Provide either:
+
+        - A web tile provider in the form of a :class:`xyzservices.TileProvider` object.
+          See :doc:`Contextily providers <contextily:providers_deepdive>` for a list of
+          tile providers. Default is ``xyzservices.providers.OpenStreetMap.HOT``, i.e.
+          OpenStreetMap Humanitarian web tiles.
+        - A web tile provider in the form of a URL. The placeholders for the XYZ in the
+          URL need to be ``{{x}}``, ``{{y}}``, ``{{z}}``, respectively. E.g.
           ``https://{{s}}.tile.openstreetmap.org/{{z}}/{{x}}/{{y}}.png``.
-        - A local file path. The file is read with
-          :doc:`rasterio <rasterio:index>` and all bands are loaded into the
-          basemap. See
+        - A local file path. The file is read with :doc:`rasterio <rasterio:index>` and
+          all bands are loaded into the basemap. See
           :doc:`contextily:working_with_local_files`.
 
         .. important::
            Tiles are assumed to be in the Spherical Mercator projection (EPSG:3857).
-
-    lonlat : bool
-        Optional. If ``False``, coordinates in ``region`` are assumed to be
-        Spherical Mercator as opposed to longitude/latitude [Default is
-        ``True``].
-
-    wait : int
-        Optional. If the tile API is rate-limited, the number of seconds to
-        wait between a failed request and the next try [Default is ``0``].
-
-    max_retries : int
-        Optional. Total number of rejected requests allowed before contextily
-        will stop trying to fetch more tiles from a rate-limited API [Default
-        is ``2``].
-
+    lonlat
+        If ``False``, coordinates in ``region`` are assumed to be Spherical Mercator as
+        opposed to longitude/latitude.
+    wait
+        If the tile API is rate-limited, the number of seconds to wait between a failed
+        request and the next try.
+    max_retries
+        Total number of rejected requests allowed before contextily will stop trying to
+        fetch more tiles from a rate-limited API.
     zoom_adjust
         The amount to adjust a chosen zoom level if it is chosen automatically. Values
         outside of -1 to 1 are not recommended as they can lead to slow execution.
@@ -128,18 +116,16 @@ def tilemap(
     ------
     ImportError
         If ``rioxarray`` is not installed. Follow
-        :doc:`install instructions for rioxarray <rioxarray:installation>`,
-        (e.g. via ``python -m pip install rioxarray``) before using this
-        function.
+        :doc:`install instructions for rioxarray <rioxarray:installation>`, (e.g. via
+        ``python -m pip install rioxarray``) before using this function.
     """
     kwargs = self._preprocess(**kwargs)
 
     if not _HAS_RIOXARRAY:
         raise ImportError(
             "Package `rioxarray` is required to be installed to use this function. "
             "Please use `python -m pip install rioxarray` or "
-            "`mamba install -c conda-forge rioxarray` "
-            "to install the package."
+            "`mamba install -c conda-forge rioxarray` to install the package."
         )
 
     raster = load_tile_map(
@@ -152,14 +138,14 @@ def tilemap(
         zoom_adjust=zoom_adjust,
     )
 
-    # Reproject raster from Spherical Mercator (EPSG:3857) to
-    # lonlat (OGC:CRS84) if bounding box region was provided in lonlat
+    # Reproject raster from Spherical Mercator (EPSG:3857) to lonlat (OGC:CRS84) if
+    # bounding box region was provided in lonlat
     if lonlat and raster.rio.crs == "EPSG:3857":
         raster = raster.rio.reproject(dst_crs="OGC:CRS84")
         raster.gmt.gtype = 1  # set to geographic type
 
-    # Only set region if no_clip is None or False, so that plot is clipped to
-    # exact bounding box region
+    # Only set region if no_clip is None or False, so that plot is clipped to exact
+    # bounding box region
     if kwargs.get("N") in [None, False]:
         kwargs["R"] = "/".join(str(coordinate) for coordinate in region)