From 55320d3d339de0996afa8e7dc51a663c7d842153 Mon Sep 17 00:00:00 2001
From: Tim Hoffmann <2836374+timhoffm@users.noreply.github.com>
Date: Wed, 18 Dec 2024 12:17:33 +0100
Subject: [PATCH] Discourage alternate strings for 'none' linestyle

Inspired by but independent of the discussion around the representation of linestyles #29304.

For other linestyles we have a short visual representation (e.g. "--") and a name (dashed "dashed"). No linestyle currently has four accepted writings "", " ", "none", "None".

This PR recommends only to use "" (visual representation) and "none" (named representation). It discourages " " and "None".  This should guide users towards more canonical usage. We may later decide whether to deprecate the alternatives.

Note also, that we have not used the alternatives in examples.
---
 lib/matplotlib/inset.py   | 18 +++++++++---------
 lib/matplotlib/lines.py   | 18 +++++++++---------
 lib/matplotlib/patches.py | 18 +++++++++---------
 3 files changed, 27 insertions(+), 27 deletions(-)

diff --git a/lib/matplotlib/inset.py b/lib/matplotlib/inset.py
index bab69491303e..0aa54439e3a5 100644
--- a/lib/matplotlib/inset.py
+++ b/lib/matplotlib/inset.py
@@ -119,15 +119,15 @@ def set_linestyle(self, ls):
         """
         Set the linestyle of the rectangle and the connectors.
 
-        ==========================================  =================
-        linestyle                                   description
-        ==========================================  =================
-        ``'-'`` or ``'solid'``                      solid line
-        ``'--'`` or ``'dashed'``                    dashed line
-        ``'-.'`` or ``'dashdot'``                   dash-dotted line
-        ``':'`` or ``'dotted'``                     dotted line
-        ``'none'``, ``'None'``, ``' '``, or ``''``  draw nothing
-        ==========================================  =================
+        =======================================================  ================
+        linestyle                                                description
+        =======================================================  ================
+        ``'-'`` or ``'solid'``                                   solid line
+        ``'--'`` or ``'dashed'``                                 dashed line
+        ``'-.'`` or ``'dashdot'``                                dash-dotted line
+        ``':'`` or ``'dotted'``                                  dotted line
+        ``''`` or ``'none'`` (discouraged: ``'None'``, ``' '``)  draw nothing
+        =======================================================  ================
 
         Alternatively a dash tuple of the following form can be provided::
 
diff --git a/lib/matplotlib/lines.py b/lib/matplotlib/lines.py
index 65a4ccb6d950..2330403532a5 100644
--- a/lib/matplotlib/lines.py
+++ b/lib/matplotlib/lines.py
@@ -1152,15 +1152,15 @@ def set_linestyle(self, ls):
 
             - A string:
 
-              ==========================================  =================
-              linestyle                                   description
-              ==========================================  =================
-              ``'-'`` or ``'solid'``                      solid line
-              ``'--'`` or  ``'dashed'``                   dashed line
-              ``'-.'`` or  ``'dashdot'``                  dash-dotted line
-              ``':'`` or ``'dotted'``                     dotted line
-              ``'none'``, ``'None'``, ``' '``, or ``''``  draw nothing
-              ==========================================  =================
+              =======================================================  ================
+              linestyle                                                description
+              =======================================================  ================
+              ``'-'`` or ``'solid'``                                   solid line
+              ``'--'`` or ``'dashed'``                                 dashed line
+              ``'-.'`` or ``'dashdot'``                                dash-dotted line
+              ``':'`` or ``'dotted'``                                  dotted line
+              ``''`` or ``'none'`` (discouraged: ``'None'``, ``' '``)  draw nothing
+              =======================================================  ================
 
             - Alternatively a dash tuple of the following form can be
               provided::
diff --git a/lib/matplotlib/patches.py b/lib/matplotlib/patches.py
index f47c8abee32d..3b9f4a259105 100644
--- a/lib/matplotlib/patches.py
+++ b/lib/matplotlib/patches.py
@@ -445,15 +445,15 @@ def set_linestyle(self, ls):
         """
         Set the patch linestyle.
 
-        ==========================================  =================
-        linestyle                                   description
-        ==========================================  =================
-        ``'-'`` or ``'solid'``                      solid line
-        ``'--'`` or  ``'dashed'``                   dashed line
-        ``'-.'`` or  ``'dashdot'``                  dash-dotted line
-        ``':'`` or ``'dotted'``                     dotted line
-        ``'none'``, ``'None'``, ``' '``, or ``''``  draw nothing
-        ==========================================  =================
+        =======================================================  ================
+        linestyle                                                description
+        =======================================================  ================
+        ``'-'`` or ``'solid'``                                   solid line
+        ``'--'`` or ``'dashed'``                                 dashed line
+        ``'-.'`` or ``'dashdot'``                                dash-dotted line
+        ``':'`` or ``'dotted'``                                  dotted line
+        ``''`` or ``'none'`` (discouraged: ``'None'``, ``' '``)  draw nothing
+        =======================================================  ================
 
         Alternatively a dash tuple of the following form can be provided::