Use unicode when interactively displaying 3d azim/elev.

... both the degree sign and the minus sign, which look better than the
pure ascii version.

Author: anntzer

lib/mpl_toolkits/mplot3d/axes3d.py

@@ -1243,9 +1243,10 @@ def format_coord(self, xd, yd):
             return ''
 
         if self.button_pressed in self._rotate_btn:
-            return 'azimuth={:.0f} deg, elevation={:.0f} deg '.format(
-                self.azim, self.elev)
             # ignore xd and yd and display angles instead
+            return (f"azimuth={self.azim:.0f}\N{DEGREE SIGN}, "
+                    f"elevation={self.elev:.0f}\N{DEGREE SIGN}"
+                    ).replace("-", "\N{MINUS SIGN}")
 
         # nearest edge
         p0, p1 = min(self.tunit_edges(),