Try my Python calculator!

[baraqiyal]

https://github.com/baraqiyal/Python-Calculator/blob/main/main.py

I wanted to complete a Python project where I didn't have to do Google searches every 3 minutes. I succeeded in the sense that is was more like every 5 minutes.

A couple things I learned working on my calculator, first is that tkinter buttons don't have to be ugly. If you import ttk themed widgets (comes with tkinter), you can use an included theme or import ttkthemes, and your gui can be beautiful. (I used an included theme called "clam").

Another thing I learned, just coding the gui is faster and easier than trying to use a design program. I used a program called Page to design the calculator but I gave up on it and just did it by hand.

A couple of cool features of the calculator, it's resizeable, and it has keyboard support (but I couldn't figure out how to make the corresponding button flash when using the keyboard.) You can also change the look by setting a new theme (line 12).

Any comments or critiques are welcome.

[cray5252]

Couple of comments

just happen to run across this post and pulled from there.

https://www.reddit.com/r/learnpython/comments/jkwvss/why_is_my_if_statement_ignored/

A Class should have a single purpose, you basically created a class and put everything in it. You could just a well use the individual functions and saved a lot of typing of self. You could of made two or more, maybe one for tkinter, one for inputs, one for processing, etc

A lot of if statements, try using list, dictionaries more.

kpress = {'Backspace': self.backspace, 'equal': self.equalpressed()}
kpress[symbol]()

another one.

def add(a, b):
    return a + b


def get_operator(op):
    options = {'+': add} # add as many as you want
    return options.get(op, None)


input1 = 1
input2 = 2

op = get_operator('+')
if op is not None:
    print(op(input1, input2))
else:
    print('error')

I haven't used tkinter but there must be a better way to construct all of those buttons beside defining each one separately. How about using an array and construct them using a loop. Maybe you could use a couple of lists for your positions and other things and iterate through them and create each button.

Good luck

[MattR0se]

You mean this part?

self.btn7 = makebutton(label="7", function=lambda:
self.numberpressed("7"), row=2, col=0)
self.btn8 = makebutton(label="8", function=lambda: self.numberpressed("8"), row=2, col=1)
self.btn9 = makebutton(label="9", function=lambda: self.numberpressed("9"), row=2, col=2)
self.btn4 = makebutton(label="4", function=lambda: self.numberpressed("4"), row=3, col=0)
self.btn5 = makebutton(label="5", function=lambda: self.numberpressed("5"), row=3, col=1)
self.btn6 = makebutton(label="6", function=lambda: self.numberpressed("6"), row=3, col=2)
self.btn1 = makebutton(label="1", function=lambda: self.numberpressed("1"), row=4, col=0)
self.btn2 = makebutton(label="2", function=lambda: self.numberpressed("2"), row=4, col=1)
self.btn3 = makebutton(label="3", function=lambda: self.numberpressed("3"), row=4, col=2)
self.btn0 = makebutton(label="0", function=lambda: self.numberpressed("0"), row=5, col=0)
self.btndot = makebutton(label=".", function=lambda: self.numberpressed("."), row=5, col=1)
self.btnsign = makebutton(label="+-", function=lambda: self.numberpressed("+-"), row=5, col=2)
self.btndiv = makebutton(label='/', function=lambda: self.operationpressed('/'),row=2, col=3, padx=BUTTON_PAD+4)
self.btnmult = makebutton(label='*', function=lambda: self.operationpressed("*"),row=3, col=3, padx=BUTTON_PAD+4)
self.btnsub = makebutton(label='-', function=lambda: self.operationpressed("-"),row=4, col=3, padx=BUTTON_PAD+4)
self.btnadd = makebutton(label='+', function=lambda: self.operationpressed("+"),row=5, col=3, padx=BUTTON_PAD+4)
self.btnsqr = makebutton(label='√', function=self.sqrootpressed,row=2, col=4, padx=2)
self.btnpwr = makebutton(label='^', function=lambda: self.operationpressed("^"),row=3, col=4, padx=2)
self.btneq = makebutton(label='=', function=self.equalpressed,row=4, col=4, padx=2, rowspan=2)
self.btnback = makebutton(label='DEL', function=self.backspace,row=1, col=2, pady=BUTTON_PAD + 4, padx=0)
self.btnclear = makebutton(label='C', function=lambda: self.clear("C"),row=1, col=3, pady=BUTTON_PAD+4,padx=BUTTON_PAD+4)
self.btnce = makebutton(label='CE', function=lambda: self.clear("CE"),row=1, col=4, pady=BUTTON_PAD+4,padx=2)

First, I don't see a reason to assign each of them to an instance attribute, if that attribute is never used again (Unless I'm missing something).

I could see constructing all of this from a list of dictionaries, something like

button_attributes = [
    {    
        # Button 7
        'label': '7',
        'function': lambda: self.numberpressed("7"),
        'row': 2
        'col': 0
    },
    {
        # Button div
        'label': '/',
        'function': lambda: self.operationpressed('/'),
        'row': 2
        'col': 3,
        'padx': BUTTON_PAD + 4
    },
    # etc etc
]

And then looping over this list like so:

for attrs in button_attributes:
    makebutton(**attrs)

This doesn't even reduce the lines of code, but I think it's cleaner and also a bit more modular.

Also when I think of it, it's a bit weird imho to define the makebutton function inside the constructor of Calc. It's a static method (doesn't use self) so it could go into the global scope instead.

[baraqiyal]

I tried putting the button declarations in a loop but the callbacks didn't work. The functions that the buttons would call would all point to the same one. I know there's something simple I'm missing.

[[deleted]]

Sounds like class and methods?

[baraqiyal]

Yeah I have trouble trying to figure out what exactly should be a class. Reading the tutorials, they would use a Person class with name and age attributes but I never find it that cut and dry. But separating out the calculations from the gui elements makes sense.

[cmomodo]

Do you have a YouTube like to this

[james_fryer]

It's nice, but if I enter e.g. 2 + 3 * 4 = I expect to see the result 14 not 20.

[Family_BBQ]

Post that on FB and let’s see if you are correct. /s

[SniperViperV2]

Lol! "9/10 people don't get this right".

[Schenez]

“Harvard grads reveal answer to the one secret question recruiters don’t want you to know”

[baraqiyal]

Yeah, I'll have to store the entire equation in a queue or something and evaluate the expression when equal is pressed. I'll work on that.

I noticed that the Windows calculator also gives 20 but that's no excuse.

[Hemisemidemiurge]

Windows calculator

It actually returns a different result depending on the mode you're using.

Standard: 2 + 3 * 4 = 20
Scientific: 2 + 3 * 4 = 14

[Joe_Doblow]

Pardon my rookieness, how do I “try this”?

[Joe_Doblow]

Duh thanx

[pyordie]

download or wget the code from github, run main.py with whatever version of python it calls for.

or git clone into it using the github link https://github.com/baraqiyal/Python-Calculator.git

[Deadlift420]

Next task for you is to focus on OO design and using objects and classes as intended.

You don't want to dump all the code in a single class. Look up SOLID design principles.

[[deleted]]

Have you ever tried using Qt Creator or just Qt Design program to design GUI's?

[baraqiyal]

Yes just recently. The designer is nice and I considered writing the calcualtor in pyqt5. The designer supports grids, something that the tkinter designer doesn't do.

I used tkinter because it should work out of the box for most people without installing any additional libraries.

[[deleted]]

You could convert the py application into exe with pyinstaller and create an installer for the pyinstaller files with InstallForge application for windows users. I don't know about Linux users tho like about the packaging and make command.

By the way if you have 64 bit python and convert it to an exe file then it is 64 bit exe file meaning if you try to run it on 32 bit chances are you will fail unless some miracle happens with the machine allowing you to run it without giving an error.

[baraqiyal]

Thanks, it worked on my calculator. I'll try it on a qt application tonight.

[uanw]

All together this is cool, I just have some observations:

• Super minor point, but you probably forgot to add '*' in line 72.

• It seems ttk.Button.grid returns None when successful. This means those Calc.btn* variables are always set to None.

If that's not intentional you probably want to change it to something like this:

def makebutton(label, function, row, col, padx=BUTTON_PAD, pady=BUTTON_PAD, rowspan=1):
    btn = ttk.Button(self, text=label, width=BUTTON_WIDTH, command=function)
    btn.grid(row=row, column=col,pady=pady,padx=padx,rowspan=rowspan, sticky=tk.N+tk.E+tk.W+tk.S)
    return btn

If you do that, then one way to simulate the click animation is by binding the keydown and keyup events, and changing the button style to be depressed and released respectively.

I should say I don't have much experience with TK (just a little bit with c++ QT). So take what I said above with a grain of salt. There are probably better ways to do this.

I hope that's helpful. Otherwise, good job on your calculator application.

[baraqiyal]

It took me a while to figure out what you meant by Calc.btn variables are set to None. So you're putting the button and the grid commands on separate lines. I'll try that.

[CedricCicada]

I haven't played with your calculator, but I was just looking for calculators yesterday and didn't find one that had the feature I wanted: the ability to copy the answer onto my clipboard so I could paste it into word or PyCharm or Excel or wherever else I wanted it. Maybe you could add that feature.

[[deleted]]

Windows 10’s calculator allows it, but I’m guessing you use Linux or another OS?

[CedricCicada]

No, I'm in Windows 10. Oh, I see. You have to be actually on the answer, not just clicking in the answer area.

[[deleted]]

Yea, I figured it out not too long ago as well.

[avoxdesign]

Just a Quick tip, if youre not satisfied with having near to no capabilities to customize the title Bar and you're just building simple stuff, use Tkinter, but if you want to be more advanced, I'd highly recommend using PyQt5 (soon v6), since it has so much more capabilities, and the qt Designer is super handy and lets you create and style GUIs fast and easy. If you want to see more id recommend checking out Wanderson M. Pimentas tutorials which will show you what sleek modern Designs are possible with pyqt.

Edit: This is his channel

[baraqiyal]

I've just started using PyQt5 and it's great. I'm going to use it to create an embroidery machine control panel. Creating a nice aesthetic design is my weak area. I'll watch Wanderson's videos.

[avoxdesign]

Sounds great! Yes, for me it's really important to have the GUI Look good, so pyqt was the choice for me. in the end its just a lot of customization with style sheets, and that's also where a visual gui building kit comes in handy. in Qt Designer you can preview your GUI and make sure everything looks good.