Docstrings, Warnings added to Window so that bad titles and bad layout types are warned. It's crude but will be helpful. Also first time using this warnings module. Hope it's OK! New Demo Program - invisible elements shows using a column for visibility

DemoPrograms/Demo_Invisible_Elements.py

@@ -0,0 +1,27 @@
+import PySimpleGUI as sg
+
+"""
+    Demonstrates that using a Column Element to make groups of Elements appear and disappear
+    will cause the layout of the elements in the column to remain as they were.  If each individual element
+    were made invisible and then visible, then tkinter puts EACH ELEMENT on a separate row when it is made
+    visible again.  This means a row of 6 elements will become a column of 6 elements if you make each of them
+    visible one at a time.
+
+"""
+
+layout = [[sg.Column([[sg.Text('My Window')],[sg.Input(key='_IN_'), sg.B('My button', key='_OUT_')]], key='_COL_')],
+            [sg.Button('Invisible'), sg.B('Visible'), sg.Button('Exit')]]
+
+window = sg.Window('Window Title', layout)
+
+while True:             # Event Loop
+    event, values = window.Read()
+    print(event, values)
+    if event in (None, 'Exit'):
+        break
+    if event == 'Invisible':
+        window.Elem('_COL_').Update(visible=False)
+    elif event == 'Visible':
+        window.Elem('_COL_').Update(visible=True)
+
+window.Close()