Having trouble with figuring out how to loop and use isalpha() and isspace() together in a String Report

Question

I am almost done with my code but I can't figure out two things.

First, I want to be able to say "You did not enter anything!" and end the program if a person enters zero characters in the string input at the beginning of the program.

Also, in the middle I have trouble figuring out how to use isalpha() and isstring() together. For example, if the string says, "dogs and cats" the program should output "Only alphabetic letters and spaces: yes."
However, if the string only has spaces or only has alphabetic letters then it should say, "Only alphabetic letters and spaces: no."

string = input('Enter a string: ')

length = len(string)
first_character = string[:1]
last_character = string[-1:]

print ('Length: ', length)
print ('First character: ', first_character)
print ('Last character: ', last_character)

if all(c.isalpha() or c.isspace() for c in string):
    print('Only alphabetic letters and spaces: yes')
else:
    print('Only alphabetic letters and spaces: no')

if string.isdigit():
    print('Only numeric digits: yes')
else:
    print('Only numeric digits: no')

if string.islower():
    print('All lower case: yes')
else:
    print('All lower case: no')

if string.isupper():
    print('All upper case: yes')
else:
    print('All upper case: no')

Answer 1

Take advantage of the fact that empty strings evaluate to False :

string = input('Enter a string: ')
if not string:
    print("Nothing entered.")
    exit()

Use the built-in function all to help you with the next part:

if not string.isalpha() and not string.isspace() and all(i.isalpha() or i.isspace() for i in string):
    print("Passed!")

Answer 2

Well, after you get the length of the entered string with length = len(string) , immediately perform your sanity check.

if length == 0:
    # do something

Answer 3

You could check if a string is empty by using:

if (word1 == ''):
    print('Empty')

Or if the string cointains whitespaces you could clear those out by using .strip()

word2 = ' '
word2a = word2.strip()
if (word2a == ''):
    print('Empty2')