I'm trying to plot the exponential and logistic population models, but my code doesn't seem to work as well as I planned, what's wrong?

Full Code:

import numpy as np
import matplotlib.pyplot as plt
import math
from IPython.display import clear_output\
print ("Utilize Which Growth Model of Population? (Type A or B)") ;
print () ;
print ("A Exponential Growth Model") ;
print ("B Logistic Growth Model") ;
print () ;
A = int(1) ; #Exponential Growth Model
B = int(2) ; #Logistic Growth Model
C = input("Growth Model of choice : ") ;
print () ;
if C == 'A' :
#Definition of Parameters
print ("The Differential Equation of your chosen growth model is P'(t) = r*P(t)") ;
print () ;
print ("Where r = growth parameter") ;
print ("Where P(t) = total population at a certain time t") ;
print ("Where t = time") ;
print () ;
#Explanation of Differential Equation
print ("This equation can be considered as the exponential differential equation") ;
print ("because its solution is P(t) = P(0)*e^r*t ; where P(0) = Initial Population") ;
print () ;
print ("This equation can be portrayed by using this graph : ")
#Graph Code
x,y = np.meshgrid (np.linspace(-50, 50, 10), np.linspace(-50, 50, 10)) ;
r = float (input ("Encode Growth Parameter :")) ;
t = float (input ("At how many years do you want to solve? :")) ;
P = float (input ("Encode Population Count :")) ;
P = y ;
t = x ;
x = np.asarray (x, dtype='float64')
Un = (P/P*(math.exp(r*t))) #Stack_overflow help from Adam.Er8
Vn = (P/P*(math.exp(r*t))) #Stack_overflow help from Adam.Er8
plt.quiver (x, y, Un, Vn) ;
plt.plot ([8, 12, 25, 31], [1, 16, 20, 40]) ;
plt.show ()
if C == 'B' :
print ("The Differential Equation of your chosen growth model is y' = k*y*(M-y)") ;
print () ;
print ("Where k = slope of the function") ;
print ("Where y = y-value at the specific point") ;
print ("Where M = limit of y as x approaches infinity") ;
print () ;
print ("This equation is derived using *** ") ;