How to manipulating STR?

Question

I start to learn Python. Please give a review to my program:

i = input("input weight = ")

def chicken(i):
    price = 2000
    print('price /kg = ',price)
    totalprice = int(i)*price
    print('total price = ',totalprice)
chicken(i)

This program is run well if I input with number, but get an error with alphabet.

What should I do if I give an alphabet then I can do print("wrong character")?

Answer 1

This is fairly straightforward problem

i = input("input weight = ")

def chicken(i):
    price = 2000
    print('price /kg = ',price)
    totalprice = int(i)*price
    print('total price = ',totalprice)

if i.isnumeric():
    chicken(i)
else:
    print("wrong character")

Output:

input weight = a
wrong character

input weight = 5
price /kg =  2000
total price =  10000

Answer 2

try this function

The isnumeric() method returns True if all the characters are numeric (0-9), otherwise False.

i = input("input weight = ")

def chicken(i):
      if not i.isnumeric():
        print("input is not a number")
        return 1
      price = 2000
      print('price /kg = ',price)
      totalprice = int(i)*price
      print('total price = ',totalprice)
chicken(i)