当没有输入时，将Python3输入设置为默认数字

Question

我在这件事上耽搁了一段时间了，现在请帮帮我，因为我有点糊涂了

这是密码

from tkinter import*
###title/info 
root = Tk()
root.configure(background="black")
root.title("C02 caculator")
root.resizable(1,1)
root.columnconfigure(0,weight=1)
root.columnconfigure(1,weight=1)

introtext = Label(root, text=" C02 Calculator \n" 
'Made by: Ronan Shade \n'
'Date: 18/7/2018 \n '

"\n This calculator is made to find out the O/A c02 output from any given product, \n"
"using a list of modified and combined formulas . Simply weigh (in grams) the \n" 
"wight of each core part of the product and determine what marital the part \n" 
"made of. Enter the findings into the calculator and it will give you a output.\n"

"\n Data used to make the formula can be found at the following: \n"
"http://www.lowtechmagazine.com/what-is-the-embodied-energy-of-materials.html \n"
"https://www.unitjuggler.com/convert-energy-from-kgSKE-to-MJ.html \n"
"https://carbonpositivelife.com/co2-per-kwh-of-electricity/ \n"
"http://web.mit.edu/ebm/www/publications.htm \n"
,background="black",foreground="grey90")
introtext.grid(row=1,column=0, sticky=E)



root.mainloop()

### here is where the real work starts ###
def final_calculation():
    entryField.delete(0,'end') 

    Steal = float(entrySteal.get())
    Steal_recycled= float(entryRecycledSteal.get())
    Wood = float(entryWood.get())
    Aluminum_recycled = float(entryAluminumRrecycled.get())
    Aluminum = float(entryAluminum.get())
    Iorn = float(entryIron.get())
    Glass = float(entryGlass.get())
    Paper = float(entryPaper.get())
    Plastics = float(entryPlastics.get())
    Copper = float(entryCopper.get())
    Silicon = float(entrySilicon.get())
    Nickel = float(entryNickel.get())
    Titanium = float(entryTitanium.get())
    Electronic_grade_silicon= float(entryElectronicGradeSilicon.get())

    output_wood = (Wood *wood_c02)
    output_steal = (Steal * steal_c02 )
    output_Steal_recycled = (Steal_recycled*Steal_recycled_c02)
    output_Aluminum = (Aluminum*Aluminum_c02)
    output_Aluminum_recycled = (Aluminum_recycled*Aluminum_recycled_c02)
    output_Iorn = (Iorn*Iorn_c02)
    output_Glass = (Glass*Glass_c02)
    output_Paper = (Paper*Paper_c02)
    output_Plastics = (Plastics*Plastics_c02)
    output_Copper = (Copper*Copper_c02)
    output_Silicon = (Silicon*Silicon_c02)
    output_Nickel = (Nickel*Nickel_c02)
    output_Titanium = (Titanium*Titanium_c02)
    output_Electronic_grade_silicon = (Electronic_grade_silicon*Electronic_grade_silicon_c02)

    FinalMess = (output_steal + output_wood + output_Steal_recycled + output_Aluminum + output_Aluminum_recycled
    + output_Aluminum +output_Iorn + output_Glass +output_Paper + output_Plastics + output_Copper + output_Silicon
    + output_Nickel + output_Titanium + output_Electronic_grade_silicon * c02_coal)

    FinalClean="the amount of C02 in Grams = " + str (round(FinalMess,2))
    entry.set(FinalClean)

steal_c02 = float (9.73)
Steal_recycled_c02 = float (2.91)
wood_c02 = float (1.39)
Aluminum_recycled_c02 = float (3.95)
Aluminum_c02 = float (60.8)
Iorn_c02 = float (3.75)
Glass_c02 = float (7.35)
Paper_c02 = float (10.43)
Plastics_c02 = float (15.57)
Copper_c02 = float (25.65)
Silicon_c02 = float (64.6)
Nickel_c02 = float (69.45)
Titanium_c02 = float (255.5)
Electronic_grade_silicon_c02 = float (2131.8)
c02_coal =+ float (0.94) # number used to caculate kwh to C02





root = Tk()
root.configure(background="black")
root.title("C02 caculator")
root.resizable(1,1)
root.columnconfigure(0,weight=1)
root.columnconfigure(1,weight=1)

entry = StringVar()
entryField = Entry(root, textvariable=entry,background="white",foreground="black",justify=CENTER)
entryField.grid(row=0,column=0,columnspan=2,sticky=W+E)
entryField.columnconfigure(0,weight=1)

#lable for all the products 
labelWood = Label(root, text="Amount of wood :",background="black",foreground="grey90")
labelWood.grid(row=1,column=0, sticky=E)

labelSteal = Label(root, text="Amount of steal :",background="black",foreground="grey90")
labelSteal.grid(row=2,column=0, sticky=E)

labelRecycledSteal = Label(root, text="Amount of recycled steal :",background="black",foreground="grey90")
labelRecycledSteal.grid(row=3,column=0, sticky=E)

labelAluminum = Label(root, text="Amount of aluminum :",background="black",foreground="grey90")
labelAluminum.grid(row=4,column=0, sticky=E)

labelAluminumRrecycled = Label(root, text="Amount of aluminum rrecycled :",background="black",foreground="grey90")
labelAluminumRrecycled.grid(row=5,column=0, sticky=E)

labelIron = Label(root, text="Amount of iron :",background="black",foreground="grey90")
labelIron.grid(row=6,column=0, sticky=E)

labelGlass = Label(root, text="Amount of glass :",background="black",foreground="grey90")
labelGlass.grid(row=7,column=0, sticky=E)

labelPaper = Label(root, text="Amount of paper :",background="black",foreground="grey90")
labelPaper.grid(row=8,column=0, sticky=E)

labelPlastics = Label(root, text="Amount of plastics :",background="black",foreground="grey90")
labelPlastics.grid(row=9,column=0, sticky=E)

labelCopper = Label(root, text="Amount of copper :",background="black",foreground="grey90")
labelCopper.grid(row=10,column=0, sticky=E)

labelSilicon = Label(root, text="Amount of Silicon :",background="black",foreground="grey90")
labelSilicon.grid(row=11,column=0, sticky=E)

labelNickel = Label(root, text="Amount of nickel :",background="black",foreground="grey90")
labelNickel.grid(row=12,column=0, sticky=E)

labelTitanium = Label(root, text="Amount of titanium :",background="black",foreground="grey90")
labelTitanium.grid(row=13,column=0, sticky=E)

labelElectronicGradeSilicon = Label(root, text="Amount of electronic grade silicon : ",background="black",foreground="grey90")
labelElectronicGradeSilicon.grid(row=14,column=0, sticky=E)



#entry boxes 
entryWood = Entry (root,background="grey90",foreground="black") 
entryWood.grid(row=1,column=1,sticky=W)


entrySteal = Entry(root,background="grey90",foreground="black")
entrySteal.grid(row=2,column=1,sticky=W)


entryRecycledSteal = Entry(root,background="grey90",foreground="black")
entryRecycledSteal.grid(row=3,column=1,sticky=W)

entryAluminum = Entry(root,background="grey90",foreground="black")
entryAluminum.grid(row=4,column=1,sticky=W)

entryAluminumRrecycled = Entry(root,background="grey90",foreground="black")
entryAluminumRrecycled.grid(row=5,column=1,sticky=W)

entryIron = Entry(root,background="grey90",foreground="black")
entryIron.grid(row=6,column=1,sticky=W)

entryGlass = Entry(root,background="grey90",foreground="black")
entryGlass.grid(row=7,column=1,sticky=W)

entryPaper = Entry(root,background="grey90",foreground="black")
entryPaper.grid(row=8,column=1,sticky=W)

entryPlastics = Entry(root,background="grey90",foreground="black")
entryPlastics.grid(row=9,column=1,sticky=W)

entryCopper = Entry(root,background="grey90",foreground="black")
entryCopper.grid(row=10,column=1,sticky=W)

entrySilicon = Entry(root,background="grey90",foreground="black")
entrySilicon.grid(row=11,column=1,sticky=W)

entryNickel = Entry(root,background="grey90",foreground="black")
entryNickel.grid(row=12,column=1,sticky=W)

entryTitanium = Entry(root,background="grey90",foreground="black")
entryTitanium.grid(row=13,column=1,sticky=W)

entryElectronicGradeSilicon = Entry(root,background="grey90",foreground="black")
entryElectronicGradeSilicon.grid(row=14,column=1,sticky=W)

#caculate button
button = Button(root, text="caculate C02", command= final_calculation)
button.grid(row=15,columnspan=2)




root.mainloop()

正如你可能看到我的问题一大堆的输入选项，而实际上用户只需要几个，但它是一个巨大的痛苦手动输入0的每一个输入是没有被使用。有没有办法将输入默认设置为0

问候49.95

Answer 1

为所有的条目做一些事情是一件痛苦的事情，因为所有条目都是手动创建的。在循环中创建它们会更容易，这样您就可以同时对它们进行任何修改，如插入0：

materials = ['wood', 'steal', 'recycled steal', 'aluminum', 'recycled aluminum', 'iron', 'glass', 'paper', 'plastics', 'copper', 'silicon', 'nickel', 'titanium', 'electronic grade silicon']
labels = {}
entries = {}

for i, m in enumerate(materials):
    labels[m] = Label(root, text="Amount of {} :".format(m), background="black", foreground="grey90")
    labels[m].grid(row=i+1,column=0, sticky=E)

    entries[m] = Entry(root, background="grey90", foreground="black") 
    entries[m].grid(row=i+1,column=1,sticky=W)
    entries[m].insert(END, '0')

请记住，如果使用此函数，则需要重写final_calculation函数，以便按以下方式获取值：Steal = float(entries['steal'].get())

另外，您可能需要阅读entry validation，以确保条目中的内容可以转换为浮点值。你知道吗