Programming course with PySimpleGUI lessons

ProgrammingClassExamples/1e PSG (validation and Look and Feel).py

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+#PySimple examples (v 3.8)
+#Tony Crewe
+#Sep 2018
+
+import PySimpleGUI as sg
+
+#Can use a variety of themes - plus individual options
+sg.ChangeLookAndFeel('SandyBeach')    
+sg.SetOptions (font = ('Arial', 10, 'bold'))
+            
+
+layout = [ [sg.Text('Enter a Temperature in Celcius')],
+    [sg.Text('Celcius', size =(8,1)), sg.InputText(size = (15,1),key = 'input')],
+    [sg.Text('Result', size =(8,1)), sg.InputText(size = (15,1),key = 'result')],
+    [sg.ReadButton('Submit', bind_return_key = True)]]  
+
+window = sg.FlexForm('Temp Converter').Layout(layout) 
+
+while True:
+    button, value = window.Read() 
+    if button is not None:        
+        #catch program errors for text, floats or blank entry:
+        #Also validation for range [0, 50]
+        try:
+            if float(value['input']) > 50 or float(value['input']) <0:
+                sg.Popup('Error','Out of range')
+            else:
+                fahrenheit = round(9/5*int(value['input']) +32, 1)
+                window.FindElement('result').Update(fahrenheit)  #put result in text box
+        except ValueError:
+                sg.Popup('Error','Please try again')             #display error
+       
+    else:
+        break