Python3: Division by 0 error with decimals

Question

I have the following code:

    from tkinter import *

################### Variables
Screenx = "640"
Screeny = "480"
screenSize = str(Screenx + "x" + Screeny)

global BTC
BTC = 0.000123

global processor
processor = 5

global USD
USD = 150000

global Auto_Miners
Auto_Miners = 1

global Computers
Computers = 3

global MinePower
MinePower = Computers * (0.0001 * processor)

global entryText
entryText = ('empty')

global entryPurpose
entryPurpose = "Nothing"

global BTCPrice
BTCPrice = 0.5



################## Function Definitions

def Mine_BTC():
    global MinePower
    global BTC
    BTC = BTC + MinePower
    print("Mining " + str(MinePower) + " BitCoins...")
    BitCoinLabel2.config(text=str(BTC))

def Buy_AM():
    global Auto_Miners
    global USD
    if USD >= 100:
        Auto_Miners = Auto_Miners + 1
        print("Bought 1 autominer...")
        AutominersLabel1.config(text=Auto_Miners)
        USD = USD - 100
    else:
        print("Damn you are poor...")

def Buy_Computers():
    global Computers
    global USD
    if USD >= 300:
        Computers = Computers + 1
        print("Bought 1 Computer...")
        ComputerLabel1.config(text=Computers)
        USD = USD - 300
    else:
        print("Damn you are poor...")

def Buy_Processor():
    global USD
    global processor
    if USD >= 450:
        processor = processor + 1
        print("PP + 1")
        ProLabel.config(text=processor)
        USD = USD - 450
    else:
        print("What a poor man...")


def EnterButton():
    global entryText
    global entryPurpose
    global BTC
    global USD
    text_E = EntryA.get()
    print(text_E)
    if entryPurpose == ("How many USD to BTC?"):
        BTC = BTC + (int(text_E) % int(BTCPrice))
        print(BTC)
        USD = USD - text_E
        print(USD)
    elif entryPurpose == ("How many BTC to USD?"):
        USD = text_E * BTCPrice
        print(USD)
        BTC = BTC - int(text_E)
        print(BTC)










def BuyBTC():
    global entryPurpose
    print(entryPurpose)
    entryPurpose = ("How many USD to BTC?")
    print(entryPurpose)
    entryP.config(text=entryPurpose)

def SellBTC():
    entryPurpose = "How many BTC to USD?"
    entryP.config(text=entryPurpose)





################# Screen Mainloop

screen = Tk()
screen.title("BitCoin Simulator")
screen.geometry(screenSize)

canvas = Canvas()
canvas.pack()
canvas.create_line(10, 0, 10, 600)
canvas.create_rectangle(200, 30, 350, 200)



EntryA = Entry(screen, textvariable=entryText)
EntryA.place(x=150, y=300)

EntryB = Button(screen, text="Enter", bg="blue")
EntryB.config(command=EnterButton)
EntryB.place(x=170, y=350)


BitCoinLabel1 = Label(screen, text="BitCoins: ").place(x=150, y=10)
BitCoinLabel2 = Label(screen, text=str(BTC)) ###
BitCoinLabel2.place(x=220, y=10)

MineButton = Button(screen, text="Mine")
MineButton.config(command=Mine_BTC)
MineButton.place(x=150, y=30)

AutominersButton = Button(screen, text="Auto-Miners:")
AutominersButton.config(command=Buy_AM)
AutominersButton.place(x=150, y=80)

AutominersLabel1 = Label(screen, text=Auto_Miners)
AutominersLabel1.place(x=270, y=85)

ComputersButton = Button(screen, text="Computers:")
ComputersButton.config(command=Buy_Computers)
ComputersButton.place(x=150, y=120)

ComputerLabel1 = Label(screen, text=Computers)
ComputerLabel1.place(x=270, y=120)

ProButton = Button(screen, text="Processors:")
ProButton.config(command=Buy_Processor)
ProButton.place(x=150, y=180)

ProLabel = Label(screen, text=processor)
ProLabel.place(x=285, y=180)

BuyButton = Button(screen, text="BUY")
BuyButton.config(command=BuyBTC)
BuyButton.place(x=340, y=170)

SellButton = Button(screen, text="SELL")
SellButton.config(command=SellBTC)
SellButton.place(x=410, y=170)

entryP = Label(screen, text=str(entryPurpose))
entryP.place(x=150, y=270)




screen.mainloop()

The above code is a little program im working on about BitCoin, it isnt finished.

In line 88 I have this code: BTC = BTC + (int(text_E) % int(BTCPrice))

I get a Division by 0 error... text_E is never 0. BTCPrice is set to 0.01. If i change that to something like 9 or 6578 I dont get the error. So im guessing that it takes the decimal number (and not just 0.01; 0.88 and 0.02828 too) as a 0. I tried dividing using / and %, but I get the same result. Can somebody tell me how to fix this? Thanks

you are converting the number from `double` to `int` hence all decimal number convert to int (rounded). Hence all value start with `0.` convert to `0`. Just use the statement like `(text_E % BTCPrice)` — Abhijit Pritam Dutta, Oct 14 '17 at 19:11
That is too much code for us to understand. Please condense it down to a [mcve] — Bryan Oakley, Oct 15 '17 at 13:07

score 0 · Answer 1 · answered Oct 14 '17 at 21:56

The int function always rounds the input down to the nearest integer. int(0.01) evaluates to 0, because the largest integer less than 0.01 is 0. I personally don't see why you are turning BTCPrice into an integer, but hey, I'm just here to answer your question.

Some other things, though:

If you declare a variable at the global level, there is no need to say global variable. global is only used when modifying a variable from within a different scope.

Instead of writing BTC = BTC + (int(text_E) % int(BTCPrice)), you can just write BTC += (int(text_E) % int(BTCPrice)). This is a compound statement. In general, x += y just means x = x + y. This also applies to -=, *=, /=, **= (exponentiation), and %=.

Python3: Division by 0 error with decimals

1 Answers1