Add 'all'/'both'/'neither' options for label sides

docs/projections.py

@@ -186,7 +186,7 @@
 #      <https://scitools.org.uk/cartopy/docs/latest/gallery/lines_and_polygons/always_circular_stereo.html>`__
 #      from the cartopy website). To disable this feature, set :rcraw:`geo.round` to
 #      ``False`` or pass ``round=False` to `~proplot.axes.GeoAxes.format`. Please note
-#      that cartopy cannot add gridline labels to polar plots with circular boundaries.
+#      that older versions of cartopy cannot add gridlines to maps bounded by circles.
 #    * To make things more consistent, the `~proplot.constructor.Proj` constructor
 #      function lets you supply native `PROJ <https://proj.org>`__ keyword names
 #      for the cartopy `~cartopy.crs.Projection` classes (e.g., `lon0` instead
@@ -212,15 +212,17 @@
     ax2 = fig.subplot(gs[i, 1], proj=proj, backend='basemap')  # basemap backend
 
 # Format projections
-fig.format(
+axs = fig.subplotgrid
+axs.format(
     land=True,
     suptitle='Figure with several projections',
     toplabels=('Cartopy examples', 'Basemap examples'),
     toplabelweight='normal',
     latlines=30, lonlines=60,
-    lonlabels='b', latlabels='r',  # or lonlabels=True, labels=True, etc.
 )
-fig.subplotgrid[-2:].format(latlines=20, lonlines=30)  # dense gridlines for polar plots
+axs[:2].format(lonlabels='b', latlabels='r')  # or lonlabels=True, lonlabels='bottom',
+axs[2:4].format(lonlabels=False, latlabels='both')
+axs[4:].format(lonlabels='all', lonlines=30)
 pplt.rc.reset()
 
 

proplot/axes/geo.py

@@ -99,19 +99,22 @@
     which sides of the map. Use the keyword `labels` to set both at once. The
     argument must conform to one of the following options:
 
-    1. A boolean. ``True`` indicates the left side for latitudes, bottom
-       side for longitudes, and ``False`` disables all labels.
-    2. A string or sequence of strings indicating the side names, e.g.
-       ``'left'`` for latitudes or ``('top', 'bottom')`` for longitudes.
-    3. A string indicating the side names with single characters, e.g.
-       ``'lr'`` for latitudes or ``'bt'`` for longitudes.
-    4. A boolean 2-tuple indicating whether to draw labels on the
-       ``(left, right)`` sides for latitudes, or ``(bottom, top)``
-       sides for longitudes.
-    5. A boolean 4-tuple indicating whether to draw labels on the
-       ``(left, right, bottom, top)`` sides, as with the basemap
-       `~mpl_toolkits.basemap.Basemap.drawmeridians` and
-       `~mpl_toolkits.basemap.Basemap.drawparallels` `labels` keyword.
+    * A boolean. ``True`` indicates the bottom side for longitudes and
+      the left side for latitudes, and ``False`` disables all labels.
+    * A string or sequence of strings indicating the side names, e.g.
+      ``'top'`` for longitudes or ``('left', 'right')`` for latitudes.
+    * A string indicating the side names with single characters, e.g.
+      ``'bt'`` for longitudes or ``'lr'`` for latitudes.
+    * A string matching ``'neither'`` (no labels), ``'both'`` (equivalent
+      to ``'bt'`` for longitudes and ``'lr'`` for latitudes), or ``'all'``
+      (equivalent to ``'lrbt'``, i.e. all sides).
+    * A boolean 2-tuple indicating whether to draw labels
+      on the ``(bottom, top)`` sides for longitudes,
+      and the ``(left, right)`` sides for latitudes.
+    * A boolean 4-tuple indicating whether to draw labels on the
+      ``(left, right, bottom, top)`` sides, as with the basemap
+      `~mpl_toolkits.basemap.Basemap.drawmeridians` and
+      `~mpl_toolkits.basemap.Basemap.drawparallels` `labels` keyword.
 
 loninline, latinline, inlinelabels : bool, default: :rc:`grid.inlinelabels`
     *For cartopy axes only.*
@@ -502,12 +505,18 @@ def _to_label_array(arg, lon=True):
             array = [False] * 5
             opts = ('left', 'right', 'bottom', 'top', 'geo')
             for string in strings:
-                if string in opts:
+                if string == 'all':
+                    string = 'lrbt'
+                elif string == 'both':
+                    string = 'bt' if lon else 'lr'
+                elif string == 'neither':
+                    string = ''
+                elif string in opts:
                     string = string[0]
-                elif set(string) - set('lrbtg'):
+                if set(string) - set('lrbtg'):
                     raise ValueError(
                         f'Invalid {which}label string {string!r}. Must be one of '
-                        + ', '.join(map(repr, opts))
+                        + ', '.join(map(repr, (*opts, 'neither', 'both', 'all')))
                         + " or a string of single-letter characters like 'lr'."
                     )
                 for char in string: