From 51784a9bb3cb279f663eeb2b07ed9a64df54012d Mon Sep 17 00:00:00 2001
From: chrissshe <chrissshe@gmail.com>
Date: Mon, 17 Feb 2020 19:35:42 -0800
Subject: [PATCH 1/3] add more comments. add a reference section

---
 examples/widgets/textbox.py | 26 ++++++++++++++++++++++----
 1 file changed, 22 insertions(+), 4 deletions(-)

diff --git a/examples/widgets/textbox.py b/examples/widgets/textbox.py
index b3c786014b6c..1f233fbd6594 100644
--- a/examples/widgets/textbox.py
+++ b/examples/widgets/textbox.py
@@ -5,9 +5,13 @@
 
 Allowing text input with the Textbox widget.
 
-You can use the Textbox widget to let users provide any text that needs to be
-displayed, including formulas. You can use a submit button to create plots
-with the given input.
+You can use the Textbox widget to let users interactively provide any text 
+that needs to be displayed, including formulas. You can use a submit button to 
+create plots with the given input.
+
+Note to not get confused with 
+:doc:`/tutorials/text/annotations` and 
+:doc:`/gallery/recipes/placing_text_boxes`, both of which are static elements.
 """
 
 import numpy as np
@@ -22,7 +26,9 @@
 
 
 def submit(text):
-    ydata = eval(text)
+    # user can enter a new math expression that uses "t" as its independent 
+    # variable. The plot refreshes on entering. Example: try "t ** 3"
+    ydata = eval(text)  
     l.set_ydata(ydata)
     ax.set_ylim(np.min(ydata), np.max(ydata))
     plt.draw()
@@ -32,3 +38,15 @@ def submit(text):
 text_box.on_submit(submit)
 
 plt.show()
+
+#############################################################################
+#
+# ------------
+#
+# References
+# """"""""""
+#
+# The use of the following functions, methods, classes and modules is shown
+# in this example:
+
+from matplotlib.widgets import TextBox

From 104f385b026604efaa20b8d9cdad51360ae04a88 Mon Sep 17 00:00:00 2001
From: Chris <chrissshe@gmail.com>
Date: Tue, 18 Feb 2020 18:49:58 -0800
Subject: [PATCH 2/3] Resolve comments on flake8 violations and improve
 docstrings

---
 .flake8                     |  1 +
 examples/widgets/textbox.py | 31 +++++++++++++++++--------------
 2 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/.flake8 b/.flake8
index 3bbcf1ded796..68b0c555fd0a 100644
--- a/.flake8
+++ b/.flake8
@@ -262,3 +262,4 @@ per-file-ignores =
     examples/userdemo/connectionstyle_demo.py: E402
     examples/userdemo/custom_boxstyle01.py: E402
     examples/userdemo/pgf_preamble_sgskip.py: E402
+    examples/widgets/textbox.py: E402
diff --git a/examples/widgets/textbox.py b/examples/widgets/textbox.py
index 1f233fbd6594..f93b72f134e3 100644
--- a/examples/widgets/textbox.py
+++ b/examples/widgets/textbox.py
@@ -3,15 +3,14 @@
 Textbox
 =======
 
-Allowing text input with the Textbox widget.
-
-You can use the Textbox widget to let users interactively provide any text 
-that needs to be displayed, including formulas. You can use a submit button to 
-create plots with the given input.
-
-Note to not get confused with 
-:doc:`/tutorials/text/annotations` and 
-:doc:`/gallery/recipes/placing_text_boxes`, both of which are static elements.
+The Textbox widget lets users interactively provide text input, including
+formulas. In this example, the plot is updated using the `.on_submit` method.
+This method triggers the execution of the `submit` function when the user
+presses enter in the textbox or leaves the textbox. 
+
+Note:  The `Textbox` widget is different from the following static elements:
+:doc:`/tutorials/text/annotations` and
+:doc:`/gallery/recipes/placing_text_boxes`.
 """
 
 import numpy as np
@@ -22,13 +21,17 @@
 t = np.arange(-2.0, 2.0, 0.001)
 s = t ** 2
 initial_text = "t ** 2"
-l, = plt.plot(t, s, lw=2)
+l, = plt.plot(t, s, lw=2)  # make a plot for the math expression "t ** 2"
+
 
+def submit(expression):
+    """
+    Update the plotted function to the new math *expression*.
 
-def submit(text):
-    # user can enter a new math expression that uses "t" as its independent 
-    # variable. The plot refreshes on entering. Example: try "t ** 3"
-    ydata = eval(text)  
+    *expession* is a string using "t" as its independent variable, e.g.
+    "t ** 3".
+    """
+    ydata = eval(expression)
     l.set_ydata(ydata)
     ax.set_ylim(np.min(ydata), np.max(ydata))
     plt.draw()

From 4f6b9f3fd8fe2ec08f4d9face86f6069c6a8ca95 Mon Sep 17 00:00:00 2001
From: Chris <chrissshe@gmail.com>
Date: Wed, 19 Feb 2020 18:22:36 -0800
Subject: [PATCH 3/3] minor fix to address CI failures

---
 examples/widgets/textbox.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/examples/widgets/textbox.py b/examples/widgets/textbox.py
index f93b72f134e3..96d1133686d9 100644
--- a/examples/widgets/textbox.py
+++ b/examples/widgets/textbox.py
@@ -5,11 +5,11 @@
 
 The Textbox widget lets users interactively provide text input, including
 formulas. In this example, the plot is updated using the `.on_submit` method.
-This method triggers the execution of the `submit` function when the user
-presses enter in the textbox or leaves the textbox. 
+This method triggers the execution of the *submit* function when the
+user presses enter in the textbox or leaves the textbox.
 
-Note:  The `Textbox` widget is different from the following static elements:
-:doc:`/tutorials/text/annotations` and
+Note:  The `matplotlib.widgets.TextBox` widget is different from the following
+static elements: :doc:`/tutorials/text/annotations` and
 :doc:`/gallery/recipes/placing_text_boxes`.
 """