材料计算器：将材料数量除以单位成本

Question

我正在尝试创建一个 GUI，允许用户计算 3D 打印作业所用材料的成本。

用户应选择打印机和材料，然后输入使用的材料量（从打印机软件手动获取）。然后，GUI 应根据材料和用户输入的金额显示材料成本。

目前，“材料成本”(£) 标题下方没有显示任何内容，因为我无法将它们链接起来。

下面是我的代码：

import tkinter as tk
from tkinter import ttk

app = tk.Tk()

app.geometry("500x250")
app.title("AM Materials Cost")
app.maxsize(500,250)
app.minsize(500,250)

# title

Label(text="Additive Manufacturing \\nMaterial Cost Calculator", fg="black", width="20", height="2",     font=("Calibri", 16)).place(x=200, y=10)

# printer text line

Label(text="Select Printer", fg="black", width="20", height="2", font=("Calibri", 11)).place(x=50, y=75)

#material text line
Label(text="Select Material", fg="black", width="20", height="2", font=("Calibri", 11)).place(x=290, y=75)

def clear_text():
text.delete(0, END)

def pick_material(e):
    if printer_combo.get() == "Fortus":
    material_combo.config(value=fortus_materials)
    if printer_combo.get() == "Markforged":
    material_combo.config(value=markforged_materials)  
    if printer_combo.get() == "Polyjet":
    material_combo.config(value=polyjet_materials)

#create list of printers
printers = [
"Fortus",
"Markforged",
"Polyjet"
]

#create list of printers and associated materials
fortus_materials = [
"ASA",
"ABS-ESD7",
"PC-ABS",
"Ultem"
]
markforged_materials = [
"Carbon Fiber",
"Onyx"
]
polyjet_materials = [
"TangoBlack",
"VeroClear",
"VeroWhite",
"Digital ABS",
]

#material price per unit - amend value within " "
asa_ppu = ["0.17"]
absesd7_ppu = ["0.19"]
pc_ppu = ["0.19"]
ultem_ppu= ["0.33"]
carbonfiber_ppu = ["1.00"]
onyx_ppu = ["0.19"]
tangoblack_ppu = ["0.25"]
veroclear_ppu = ["0.28"]
verowhite_ppu = ["0.18"]
digitalabs_ppu = ["0.30"]

#create dropdown box
printer_combo = ttk.Combobox(app, value=printers)
printer_combo.place(x=60, y=110)

#material combobox
material_combo = ttk.Combobox(app, value=[""])
material_combo.place(x=300, y=110)

#material amount text line
Label(text="Enter Material Amount", fg="black", width="20", height="1", font=("Calibri", 11)).place(x=50, y=145)

#material cost text line
Label(text="Cost of Material (£):", fg="black", width="20", height="1", font=("Calibri", 11)).place(x=290, y=145)

#entry box for amount
e = Entry(app,justify="center")
e.place(x=70, y=175)
e.delete(0,'end')

#material cost output
def myClick():
myLabel = Label(app, text='', height="1", font=("Calibri", 20))
myLabel.place(x=340, y=163)

#calculate button
myButton = Button(app, text="Calculate", command=myClick)
myButton.place(x=220, y=170)

#close button
exit_button = Button(app, text="Close", command=app.destroy)
exit_button.place(x=450, y=215)