为什么两个不同的代码给出相同的输出？

Question

我正在尝试建立一个计算器。我为排列计算编码，并且效果很好。但是当我尝试组合时，结果却不是我期望的。谁能指出错误？

代码：

from math import *    
x = ""    
y = ""    
z = ""    
x = input("input data1 ")    
y = input("input data2 ")    
z = input("input data3 ")    
if y == "+"   :    
    result = float(x) + float(z)
elif y == "P" or "p" :    
    q = int(z)    
    r = int(x)    
    result = 1    
    i = 1    
    while i <= q:    
        result = result*r    
        r =r-1    
        i = i+1    
elif y == "C" or "c" :    
    q = int(z)    
    r = int(x)    
    result = 1    
    i = 1    
    while i <= q:    
        result = result*r    
        result = result/i    
        r =r-1    
        i = i+1  

print("the answer is " +str(result))    

C:\Users\USER\PycharmProjects\lel\venv\Scripts\python.exe C:/Users/USER/PycharmProjects/lel/lel01.py

input data1 3    
input data2 c    
input data3 3    
the answer is 6    
Process finished with exit code 0