Python腳本運行失敗if/else塊

Question

運行以下操作，只運行menu（）函數，if/else塊都不起作用。

def menu(): 
    print(''' 
    1-addition 
    2-subtraction 
    3-multiplication 
    4-devision 
    ''') 

import random 

def multiplication_random(number1,number2): 
    c=number1*number2 
    return c 
    num11 = random.randint (1,1000) 
    num21 = random.randint (1,1000) 
    print("these are going to be multiplied, they are random numbers:") 


def devision_random(number1,number2): 
    c=number1/number2 
    return c 
    num22 =random.randint (1,1000) 
    num12 = num2 * random.randint (1,1000) 
    print("these are going to be devided, they are random numbers:") 

def subtract_random(number1,number2): 
    c=number1-number2 
    return c 
    num13 = random.randint (1,1000) 
    num23 = random.randint (1,1000) 
    print("these are going to be subtracted, they are random numbers:") 

def add_random(number1,number2): 
    c=number1+number2 
    return c 
    num14 = random.randint (1,1000) 
    num24 = random.randint (1,1000) 
    print("these are going to be added, they are random numbers:") 

menu() 

choice = input('pick a number from the menu') 

if choice == 1: 
    add_random(number1,number2) 
    print(num14) 
    print(num24) 
    print(add_random(num11,num21)) 

elif choice == 2: 
    subtract_random(number1,number2) 
    print(num13) 
    print(num23) 
    print(subtract_random(num12,num22)) 

elif choice == 3: 
    multiplication_random(number1,number2) 
    print(num11) 
    print(num21) 
    print(multiplication_random(num13,num23)) 

elif choice == 4: 
    devision_random(number1,number2) 
    print(num12) 
    print(num22) 
    print(devision_random(num14,num24)) 

我使用Python 3.5

Answer 1

input()返回一個字符串，但所有的if語句檢查一個整數。因此，條件永遠不會是真實的，例如字符串"1"不等於整數1。

變化

choice = input('pick a number from the menu') 

到

choice = int(input('pick a number from the menu')) 

，你應該取得一些進展。

完成更改後，可能需要添加一些錯誤檢查以處理用戶輸入無法轉換爲有效整數的字符串的情況。您可以使用try/except這樣的：

try: 
    choice = input('pick a number from the menu') 
    choice = int(choice) 
    ... # rest of your code goes here 
except ValueError: 
    print("Invalid choice {!r} made".format(choice)) 

Answer 2

以下是完整的程序：

def menu(): 
print(''' 
******************** 
* 1-addition  * 
* 2-subtraction * 
* 3-multiplication * 
* 4-devision  * 
* 5-quit   * 
******************** 
''') 


import time 
import random 



def multiplication_random(number14,number24): 
    c=number14*number24 
    return c 
    print("these are going to be multiplied, they are random numbers:") 




def devision_random(number1,number2): 
    c=number1/number2 
    return c 
    print("these are going to be devided, they are random numbers:") 



def subtract_random(number13,number23): 
    c=number13-number23 
    return c 
    print("these are going to be subtracted, they are random numbers:") 



def add_random(number11,number21): 
    c=number11+number21 
    return c 
    print("these are going to be added, they are random numbers:") 




menu() 
choice = int(input('pick a number from the menu')) 

if choice == 1: 
    number11 = random.randint (1,1000) 
    number21 = random.randint (1,1000) 
    print(number11,'+',number21) 
    time.sleep(0.5) 
    print('calculating...') 
    time.sleep(0.5) 
    print(add_random(number11,number21)) 

elif choice == 2: 
    number13 = random.randint (1,1000) 
    number23 = random.randint (1,1000) 
    print(number13,'-',number23) 
    time.sleep(0.5) 
    print('calculating...') 
    time.sleep(0.5) 
    print(subtract_random(number13,number23)) 


elif choice == 3: 
    number14 = random.randint (1,1000) 
    number24 = random.randint (1,1000) 
    print(number14,'*',number24) 
    time.sleep(0.5) 
    print('calculating...') 
    time.sleep(0.5) 
    print(multiplication_random(number14,number24)) 

elif choice == 4: 
    number2 =random.randint (1,1000) 
    number1 = number2 * random.randint (1,1000) 
    print(number1,'/',number2) 
    time.sleep(0.5) 
    print('calculating...') 
    time.sleep(0.5) 
    print(devision_random(number1,number2)) 

elif choice == 5: 
    print('Goodbye') 
    print('  z') 
    print('  z') 
    print('  z') 
    print(' z') 
    print(' z') 
    print(' 0') 
    print('/|\\') 
    print('/ \\') 







''' 
Thank you for your help 
'''