Why do I get a type error when trying to change value of tkinter's entry boxes to numbers?-CodePudding

a = IntVar(root, aEntry.get())
b = IntVar(root, bEntry.get())
c = IntVar(root, cEntry.get())

y = a*x**2   b*x   c

This gives me this error: "TypeError: unsupported operand type(s) for *: 'IntVar' and 'float'". If it helps, I am trying to use that equation to draw a quadratic graph using numpy and matplotlib.

CodePudding user response：

You're multiplying the IntVar object itself, which is wrong.

Instead, you want to multiply the value that is stored inside the IntVar. Use .get() to fetch the value.

y = a.get() * x**2   b.get() * x   c.get()

CodePudding user response：

You don't need to use IntVar at all, just convert the content from those entries to integer:

try:
    a = int(aEntry.get())
    b = int(bEntry.get())
    c = int(cEntry.get())

    y = a * x**2   b * x   c
except ValueError as ex:
    print(ex)