while True:
try:
gen_0_value = int(input("Please enter a generation 0 value for the population of greenflies "))
except ValueError:
print("Sorry, could you please enter a valid number")
continue
else:
break
Is this exactly how it’s indented in your code? If so, it’ll be to do with the indentation.
just asking whats wrong with the indention’s as i’m a bit new to how to indent things properly.