except ValueError… i dont know how to fix it

import math
import numpy as np
import matplotlib.pyplot as plt

print("y = a^x + b")
jarda=0
while jarda<=0 or jarda==1:
 jarda=int(input("zadej a "))

def v() :
 while True:
   slo=(input("zadej b "))
   try :
return int (slo)
  except ValueError
 print("nebylo zadan slo")
barca=b()

A = int (input("zadej poten hodnotu def.oboru "))
B = int (input("zadej konenou hodnotu def.oboru "))

if barca>=0:
 print("Px nen")
else:
 print("Px je:[0; ",(math.log(-barca,jarda)))
 print("Py je:[0; ",(jarda0+barca))
if barca<=0:
 print("Py nen")
else:
 print("Py je:[0; ",(jarda0+barca))

x= np.linspace(A,B)
y = jarda**x+barca

plt.plot(x,y, color="pink")
plt.axhline(y=0,color="black")
plt.axvline(x=0,color="orange")
plt.xlabel("x")
plt.ylabel("y")
plt.box(True)
plt.grid(True)
plt.title("exponenciln funkce")