I think you don't need the length of string you want to calculate the digit in the length of string.
you can use this code :-
your_string = 'qwertyuiop'
print len(str(len(your_string)))
Output:
2
you want to know the number of terms ???
for example :-
s = python is a script language
then it should return 5
for that you can use this code
print len(s.split(' '))
where s.split(' ') will proivde you list (['python', 'is', 'a', 'script', 'language'])
and len(s.split(' ')) will return the number of terms in s (5)
try it it may help you
thanks for reading my reply
Here is my solutions for your query :-
sentence = input('enter :-')
word_list = sentence.split(" ")
print (len(word_list))