# python

## May 21, 2020

I have added a few more maths functions to the application and also provided a clear function. There are still a few items to add to help improve debugging but the application is starting to take shape.

Notes

window = Tk()
window.title('Maths Application')
window.geometry("570x150") # w x h
window.resizable(0,0)

1. The above code is being modified as I go. So I am changing the window size depending on what is being displayed.

2. I have also made the Window title reflect the purpose of the application.

3. That the source code now has 'result' as a label rather than output. This will show up future screenshots.

The code for the above is as follows.

#!/usr/bin/env python
import Tkinter # note use of caps
from Tkinter import *

window = Tk()
window.title('Maths Application')
window.geometry("570x150") # w x h
window.resizable(0,0)

#define button actions
def btn1():
#convert box text in to integers
ent1 = int(entrytext.get())
ent2 = int(entrytext2.get())

#insert value of variable add in	to box outtext

def btn2():
#print("subtraction")
ent1 = int(entrytext.get())
ent2 = int(entrytext2.get())

#subtract the 2 integers and store in variable sub
sub = (ent1 - ent2)

#insert value of variable sub in	to box outtext
outtext1.insert(0,str(sub)) # insert response

def btn3():
#print("multiply")
ent1 = int(entrytext.get())
ent2 = int(entrytext2.get())

#multiply the 2 integers and store in variable mul
mul = (ent1 * ent2)

#insert value of variable mul in	to box outtext
outtext1.insert(0,str(mul)) # insert response

def btn4():
#print("divide")
ent1 = int(entrytext.get())
ent2 = int(entrytext2.get())

#multiply the 2 integers and store in variable div
div = (ent1 / ent2)

#insert value of variable mul in	to box outtext
outtext1.insert(0,str(div)) # insert response

#clear boxes
def clear():
#print("clear boxes") # leave in for legacy testing
entrytext.delete(0, END) # clear input box
entrytext2.delete(0, END) # clear input box2
outtext1.delete(0, END) # clear output box

btn_tog2 = Button( window, text ='+', command=btn1) # add
btn_tog3 = Button( window, text ='-', command=btn2)  # subtract
btn_tog4 = Button( window, text ='x', command=btn3) #multiply
btn_tog5 = Button( window, text ='/', command=btn4) #divide
btn_tog6 = Button( window, text ='Clear', command=clear) #clear
btn_exit = Button( window, text ='Exit',command=exit)	 #exit

# define some labels
box1 = Label(window, text="1st Value")
box2 = Label(window, text="2nd Value")
box3 = Label(window, text="Result")

#define entry box
entry1 = StringVar() # this is our entry box
entry2 = StringVar()
entrytext = Entry(window, textvariable=entry1) # this is our entry box
entrytext2 = Entry(window, textvariable=entry2) # this is our second entry box

#define out box

entry2 = StringVar() # this is our output box
outtext1 = Entry(window, textvariable=entry2) # this is our output box

#display boxes
entrytext.grid(row = 3, column = 2,)  #display entry box
entrytext2.grid(row = 3, column = 3,)  #display entry box
outtext1.grid(row = 3, column = 4,) #display output box

#place labels
box1.grid(row = 1	, column = 2, padx = 5, pady = 5)
box2.grid(row = 1	, column = 3, padx = 5, pady = 5)
box3.grid(row = 1	, column = 4, padx = 5, pady = 5)

#buttons
btn_tog3.grid(row = 4, column = 3, padx = 1, pady = 1) # subtraction button
btn_tog4.grid(row = 5, column = 2, padx = 1, pady = 1) # multiply button
btn_tog5.grid(row = 5, column = 3, padx = 1, pady = 1) # divide button
btn_tog6.grid(row = 4, column = 6, padx = 1, pady = 1) # clear button
btn_exit.grid(row = 3, column = 6, padx = 1, pady = 1) # exit button

window.mainloop()



The code that I used for a previous application to detect if numerical values have been used is below but provided 'as is' for now.

def response():

msg = "error : must be a text value"

i = circletext.get()
y = i.isdigit()
l = len(circletext.get())
#print l
if y == True or l == 0:
circletext.insert(0,(msg))

else:
x = random.choice(RESPONSES)
circletext2.delete(0, END) # clear prev output
circletext2.insert(0,str(x)) # insert response


I will integrate a version of this in to the main code.

Happy to provide help and support via decentralised social media. I can be contacted on Mastodon here. You can get a free account on the http://qoto.org instance by following this link.

Licenced under Attribution 4.0 International (CC BY 4.0)

## May 20, 2020

So following on from the previous posts, I am how sharing a small application, that makes use of what we have been learning.

This presents 2 input boxes and an output box, any values entered in to the first two, the sum is placed in to the last box.

This is not perfect, but getting there slowly.

We need to:-

• Fix the name of the button from button1
• Detect if the user has entered numerical values
• Detect for empty boxes
• Make labels more useful

The code for the above is as follows.

#!/usr/bin/env python
import Tkinter # note use of caps
from Tkinter import *

window = Tk()
window.title('App 1')
window.geometry("650x125") # w x h
window.resizable(0,0)

#define button actions
def btn1():
#convert box text in to integers
ent1 = int(entrytext.get())
ent2 = int(entrytext2.get())

#instert value add in	to box outtext

btn_tog2 = Button( window, text ='button1', command=btn1)
btn_exit = Button( window, text ='exit',command=exit)

# define some labels
box1 = Label(window, text="Entry 1: ")
box2 = Label(window, text="Entry 2: ")
box3 = Label(window, text="Ouput1: ")

#define entry box
entry1 = StringVar() # this is our entry box
entry2 = StringVar()
entrytext = Entry(window, textvariable=entry1) # this is our entry box
entrytext2 = Entry(window, textvariable=entry2) # this is our second entry box

#define out box

entry2 = StringVar() # this is our output box
outtext1 = Entry(window, textvariable=entry2) # this is our output box

#display boxes
entrytext.grid(row = 3, column = 2,)  #display entry box
entrytext2.grid(row = 3, column = 3,)  #display entry box
outtext1.grid(row = 3, column = 4,) #display output box

#place labels
box1.grid(row = 1	, column = 2, padx = 5, pady = 5)
box2.grid(row = 1	, column = 3, padx = 5, pady = 5)
box3.grid(row = 1	, column = 4, padx = 5, pady = 5)

#buttons
btn_tog2.grid(row = 3, column = 5, padx = 5, pady = 5)
btn_exit.grid(row = 3, column = 6, padx = 5, pady = 5)

window.mainloop()



Happy to provide help and support via decentralised social media. I can be contacted on Mastodon here. You can get a free account on the http://qoto.org instance by following this link.

Licenced under Attribution 4.0 International (CC BY 4.0)

## May 19, 2020

More improvements

So last time we added some text boxes and made the application a little more presentable. Now we are going to do is add some labels above the boxes to help describe what they do.

Add this above were we define the entry boxes

# define some labels
box1 = Label(window, text="Entry 1: ")
box2 = Label(window, text="Entry 2: ")
box3 = Label(window, text="Ouput1: ")



Now add this below where we place the entry boxes but above window.mainloop()

#place labels
box1.grid(row = 1	, column = 2, padx = 5, pady = 5)
box2.grid(row = 1	, column = 3, padx = 5, pady = 5)
box3.grid(row = 1	, column = 4, padx = 5, pady = 5)


So here we have a window, with three text boxes.

So again we have something that looks a little more like an application.

## May 18, 2020

Tidying up our application

So my last post produced something that did not really look very good. So I have now tidied the code up a little bit to make it look better.

So one of the useful things within this is to adjust the dimensions of our application, so everything fits in to the window area nicely, but not leave too much empty space.

#!/usr/bin/env python
import Tkinter # note use of caps
from Tkinter import *

window = Tk()
window.title('App 1')
window.geometry("600x50") # w x h
window.resizable(0,0)

#define entry box

entry1 = StringVar() # this is our entry box
entrytext = Entry(window, textvariable=entry1) # this is our entry box
entrytext2 = Entry(window, textvariable=entry1) # this is our second entry box
#define out box

entry2 = StringVar() # this is our output box
outtext1 = Entry(window, textvariable=entry2) # this is our output box

#display boxes
entrytext.grid(row = 3, column = 2,)  #display entry box
entrytext2.grid(row = 3, column = 3,)  #display entry box
outtext1.grid(row = 3, column = 4,) #display output box

window.mainloop()



So here we have a window, with three text boxes.

Which is starting to look a little better. The main bit of advice I can give here, is test, test and test again, that way you know your application is working as you go.

## May 17, 2020

More tkinter : Add entry and text box

This code adds a box to our application, a box can serve either as a text output box OR a text entry box.

Note I have included the whole program here. I have also defined the size of our application.

While the window is bigger and the boxes are at the top, the idea is that it just displays those boxes. We can tidy things up later.

#!/usr/bin/env python
import Tkinter # note use of caps
from Tkinter import *

window = Tk()
window.title('GUI Tkinter 1')
window.geometry("300x250") # w x h
window.resizable(0,0)

#define entry box

circleVar = StringVar()
circletext = Entry(window, textvariable=circleVar)

#define out box

circleVar2 = StringVar()
circletext2 = Entry(window, textvariable=circleVar2)

circleVar2 = StringVar()
circletext2 = Entry(window, textvariable=circleVar2)

#display boxes
circletext.grid(row = 1, column = 2,)
circletext2.grid(row = 2, column = 2,)

window.mainloop()



We get:

## May 16, 2020

More tkinter : Combine buttons and labels.

Now that we can add a label and a button, it is time to combine the two. The following code does this.

#define functions for button(s)
def btn1():
print ("button pressed")

#create button object
btn_tog2 = Button( window, text ='button1', command=btn1)
btn_exit = Button( window, text ='exit',command=exit)

#place button object
btn_tog2.grid(row = 1, column = 2, padx = 5, pady = 5)
btn_exit.grid(row = 2, column = 2, padx = 5, pady = 5)

#define labeles
button1 = Label(window, text="press button")
button2 = Label(window, text="exit program")

#place labels
button1.grid(row = 1, column = 1, padx = 5, pady = 5)
button2.grid(row = 2, column = 1, padx = 5, pady = 5)


We get:

## May 15, 2020

So to carry on with some basic tk development, Once we can add a label, we add buttons. While buttons have a built in label, the label widget could be useful to add more description to that area of the application.

def btn1():
print ("button pressed")

btn_tog2 = Button( window, text ='button1', command=btn1)
btn_exit = Button( window, text ='exit',command=exit)

btn_tog2.grid(row = 1, column = 1, padx = 5, pady = 5)
btn_exit.grid(row = 2, column = 1, padx = 5, pady = 5)


We get:

With this we have added an event, so in this case the btn_tog2 runs the function btn1 which prints “button pressed” to the console.

## May 14, 2020

More tkinter development

So further to yesterdays post

The next step is to add some widgets to our application. It is generally useful to label any items. That way a user knows what purpose an entry box has.

If we take the code block from yesterday and add

#define labeles
box1 = Label(window, text="Entry 1: ")

#place labels
box1.grid(row = 1, column = 1, padx = 5, pady = 5)


before the window.mainloop() statement.

We get:

## May 13, 2020

Tkinter Development

A few years ago, I created a resource to explain how to create use some of the widgets within tkinter. This is a Python widget for creating graphical user interfaces (GUIs).

The following code is what you need to get started. This creates, just a single application window.

#!/usr/bin/env python
import Tkinter # note use of caps
from Tkinter import *

window = Tk()
window.title('GUI Tkinter 1')
window.geometry("300x250") # w x h
window.resizable(0,0)

window.mainloop()


This produces

Over the next few days, I will make more posts covering adding labels, buttons and entry / text boxes.

Hopefully it will be of use to someone.

## May 9, 2020

More Trinket Coding

Trinket is a web based development platform. One of it's features is the programming language blocks, which is in fact a block based front end and creates Python programs.

I am sharing these on my blog today, even though I also shared earlier in the week on LinkedIn and also on Twitteras part of the Paignton Library Virtual Code Club.

Drawing a circle

And the associated output

Drawing a star

And the associated output

I am working on a book to update my previous Nested loops guide I wrote a few years ago. This needed updating anyway so it would cover Scratch 3.0. This book / guide is work in progress, and will be typeset in $\LaTeX$ using Overleaf

Licenced under Attribution 4.0 International (CC BY 4.0)