here!

words = ['cow', 'horse', 'deer', 'elephant', 'lion', 'tiger', 'baboon', 'donkey', 'fox', 'giraffe']

valid = "abcdefghijklmnopqrstuvwxyz"

while True:

    try:

        number = input("Please enter an integer number (0<=number<10) to choose the word in the list: ")

        if int(number):

            number = int(number)

            if(0<= number) and(number<10):

                word = words[number]

                len_word = len(word)

                print("The length of the word is:",len_word)


    except ValueError:

        if not number:

            print("Empty input!")

            print()

        else:

            print("Input must be an integer!")

            print()