在Python中使用大量嵌套語句時改進代碼

Question

我最近在Matlab上的一些課程（主要側重於使用數學計算和繪圖）之後開始使用Python 3，我仍然是一個初學者。 但是我認爲創建一個計算器來計算可以隨Pokemon中的可用糖果進化的口袋妖怪的數量去使用Tkinter的GUI會很有趣。該程序工作正常，並給出了很好的結果。但是，我試圖改進我的編碼，並且此代碼包含大量嵌套的if和while語句，以及其他廣泛的變量和參數使用。我想知道如何改進這個代碼，使之更「pythonic」，或者如果這是創建一個像這樣的程序的正確方法。 預先感謝您

from tkinter import * 
    from tkinter import messagebox 


    def EvolveCalc(): 
     title = "Pokemon evolve calculator" 
     Poke = var.get() 
     Candies_total = Candies.get() 
     PAmount = Poke_amount.get() 
     if Poke == 'Pokemon': 
      messagebox.showinfo(title, 
         "Please select a Pokemon from the dropdown menu") 
     elif not PAmount.isdigit(): 
      messagebox.showinfo(title, "Please only enter numbers") 
     elif not Candies_total.isdigit(): 
      messagebox.showinfo(title, "Please only enter numbers") 
     else: 
      Candies_total = int(Candies.get()) 
      PAmount = int(Poke_amount.get()) 
      Evolve = int((Candies_total - 1)/(Pokedex[Poke] - 1)) 
      Candies_needed = (PAmount * (Pokedex[Poke] - 1)) + 1 
      if PAmount < Evolve: 
       n = 0 
       while Candies_needed <= Candies_total: 
        n = n + 1 
        PAmount = PAmount + 1 
        Candies_needed = ((PAmount) * (Pokedex[Poke] - 1)) + 1 
        Candies_total = Candies_total + 3 
        Evolve2 = int((Candies_total - 1)/(Pokedex[Poke] - 1)) 
       String1 = '''You have enough candies too evolve {0} {1}, 
       but you only have {2} {1} in storage and thus can only 
       evolve {2} {1} If you catch {3} more {1} you can now 
       evolve {4} {1}.''' 
       messagebox.showinfo(title, String1.format(Evolve, Poke, 
                  Poke_amount.get(), 
                  n, Evolve2)) 
      else: 
       m = 0 
       while Candies_total <= Candies_needed: 
        m = m + 1 
        PAmount = PAmount - 1 
        Candies_needed = ((PAmount) * (Pokedex[Poke] - 1)) + 1 
        Candies_total = Candies_total + 1 
        Evolve2 = int((Candies_total - 1)/(Pokedex[Poke] - 1)) 
       String2 = 'Transfer {0} {1} so you can evolve a total of {2} {1}.' 
       messagebox.showinfo(title, String2.format(m, Poke, Evolve2)) 


    root = Tk() 

    Pokedex = {'pidgey': 12, 
       'caterpie': 12, 
       'weedle': 12 
       } 

    root.title("Pokemon evolve calculator") 

    var = StringVar(root) 
    var.set('Pokemon') 
    choices = Pokedex.keys() 
    Pokemon = OptionMenu(root, var, *choices) 
    Pokemon.grid(column=0, row=1) 

    L1 = Label(root, text='Candies') 
    L1.grid(column=1, row=0) 

    Candies = Entry(root) 
    Candies.grid(column=1, row=1) 

    L2 = Label(root, text='Pokemon amount in storage') 
    L2.grid(column=2, row=0) 

    Poke_amount = Entry(root) 
    Poke_amount.grid(column=2, row=1) 

    Calculate = Button(root, text='Calculate', command=EvolveCalc) 
    Calculate.grid(column=1, row=2) 

    root.mainloop() 

Answer 1

1. 使用小寫字母，下劃線分隔的功能，因此EvolveCalc將evolve_calc
2. 使用小寫字母，可讀的變量，這樣Poke和Candies_total將成爲poke和total_candies

3. 這段代碼可減少

   elif not PAmount.isdigit(): 
       messagebox.showinfo(title, "Please only enter numbers") 
   elif not Candies_total.isdigit(): 
       messagebox.showinfo(title, "Please only enter numbers") 
   

   到

   elif not PAmount.isdigit() or not Candies_total.isdigit(): 
       messagebox.showinfo(title, "Please only enter numbers") 
   

4. 你Pokedex可以格式化，因此它更可讀

   Pokedex = {'pidgey': 12, 
         'caterpie': 12, 
         'weedle': 12 
         } 
   

   到

   Pokedex = { 
       'pidgey': 12, 
       'caterpie': 12, 
       'weedle': 12 
   } 
   

5. ，因爲它的格式不正確，我不能運行代碼。您的第一個else塊完成後，空格關閉。

補充建議：

• 閱讀PEP8
• 過目代碼示例
• 寫函數集裝箱式小型可重用的代碼
• 添加註釋來解釋你的一些數學