Allow for spaces in title and labels without needing double quotes

Mitigates against #247.

Author: weiji14

examples/tutorials/subplots.py

@@ -99,7 +99,7 @@
     figsize=("15c", "6c"),
     autolabel=True,
     margins=["0.1c", "0.2c"],
-    title='"My Subplot Heading"',
+    title="My Subplot Heading",
 ):
     fig.basemap(region=[0, 10, 0, 10], projection="X?", frame=["af", "WSne"], ax=[0, 0])
     fig.basemap(region=[0, 20, 0, 10], projection="X?", frame=["af", "WSne"], ax=[0, 1])
@@ -155,7 +155,7 @@
     figsize=("15c", "6c"),
     autolabel=True,
     margins=["0.3c", "0.2c"],
-    title='"My Subplot Heading"',
+    title="My Subplot Heading",
     layout=["Rl", "Cb"],
     frame="WSrt",
 ):

pygmt/src/subplot.py

@@ -135,6 +135,8 @@ def subplot(self, nrows=1, ncols=1, **kwargs):
     {XY}
     """
     kwargs = self._preprocess(**kwargs)  # pylint: disable=protected-access
+    kwargs["A"] = f'"{kwargs.get("A")}"' if kwargs.get("A") else None
+    kwargs["T"] = f'"{kwargs.get("T")}"' if kwargs.get("T") else None
 
     with Session() as lib:
         try:
@@ -196,8 +198,9 @@ def sca(self, ax=None, **kwargs):
     {V}
     """
     kwargs = self._preprocess(**kwargs)  # pylint: disable=protected-access
+    kwargs["A"] = f'"{kwargs.get("A")}"' if kwargs.get("A") else None
 
     with Session() as lib:
-        arg_str = " ".join(["set", f"{ax}", build_arg_string(kwargs)])
+        arg_str = " ".join(["set", f"{ax}", build_arg_string(kwargs)]).strip()
         lib.call_module(module="subplot", args=arg_str)
         yield

pygmt/tests/test_subplot.py

@@ -18,9 +18,9 @@ def test_subplot_basic_frame():
         with fig_ref.sca(ax=1):
             fig_ref.basemap(region=[0, 3, 0, 3], frame="+tplot1")
     with fig_test.subplot(nrows=1, ncols=2, figsize=("6c", "3c"), frame="WSne"):
-        with fig_test.sca(ax=[0, 0]):
+        with fig_test.sca(ax="0,0"):
             fig_test.basemap(region=[0, 3, 0, 3], frame="+tplot0")
-        with fig_test.sca(ax=[0, 1]):
+        with fig_test.sca(ax="0,1"):
             fig_test.basemap(region=[0, 3, 0, 3], frame="+tplot1")
     return fig_ref, fig_test
 
@@ -48,12 +48,12 @@ def test_subplot_autolabel_margins_title():
     fig_ref, fig_test = Figure(), Figure()
     kwargs = dict(nrows=2, ncols=1, figsize=("15c", "6c"))
 
-    with fig_ref.subplot(A="(1)", M="0.3c/0.1c", T='"Subplot Title"', **kwargs):
+    with fig_ref.subplot(A="(1)", M="0.3c/0.1c", T="Subplot Title", **kwargs):
         fig_ref.basemap(region=[0, 1, 2, 3], frame="WSne", c="0,0")
         fig_ref.basemap(region=[4, 5, 6, 7], frame="WSne", c="1,0")
 
     with fig_test.subplot(
-        autolabel="(1)", margins=["0.3c", "0.1c"], title='"Subplot Title"', **kwargs
+        autolabel="(1)", margins=["0.3c", "0.1c"], title="Subplot Title", **kwargs
     ):
         fig_test.basemap(region=[0, 1, 2, 3], frame="WSne", ax=[0, 0])
         fig_test.basemap(region=[4, 5, 6, 7], frame="WSne", ax=[1, 0])