<pre><code>def add(x,y):
return x +y
def sub(x,y):
return x -y
def mul(x,y):
return x *y
def div(x,y):
return x /y
invalidCount =0
print("Select Operation from below:")
print("1.Addition")
print("2.Subtraction")
print("3.Multiplication")
print("4.Division")
while True:
choice= int(input("Enter your Choice(1,2,3,4) from above:"))
if choice in (1,2,3,4):
invalidCount =0 # This line is that if after some invalid tries if user makes a valid tries then the invalid tries are reset remove this line if you want that number of invalid tries to be fixed
num1 = float(input("Enter first number :"))
num2 = float(input("Enter second number :"))
if choice == 1:
print("Addition of 2 numbers {} and {} is {} ".format(num1,num2,add(num1,num2)))
elif choice == 2:
print("Subtraction of 2 numbers {} and {} is {} ".format(num1,num2,sub(num1,num2)))
elif choice == 3:
print("Multiplication of 2 numbers {} and {} is {} ".format(num1,num2,mul(num1,num2)))
elif choice == 4:
print("Division of 2 numbers {} and {} is {} ".format(num1,num2,div(num1,num2)))
break
else:
if invalidCount <=3:
invalidCount += 1
print("Invalid Input with retry no {}".format(invalidCount))
else:
print("Exceeded maximum number of Invalid re-try")
break
</code></pre>