Program gives list of all potential substings from a given string, need to filter out substrings not in alphabetical order

Question

I have a list of all possible substrings from a given string, I need to print just the substrings that are in alphabetical order.

s = 'abcabcd'

a = len(s)

for x in range(a):
    for y in range(x,a-1):
        print(s[x:y+2])

if I change to:

for x in range(a):
    for y in range(x,a-1):
        if s[y+1] >= s[y]:
            print(s[x:y+2])

I get the exact same answer, nothing is filtered out.

Current result is the following:

ab abc abca abcab abcabc abcabcd bc bca bcab bcabc bcabcd ca cab cabc cabcd ab abc abcd bc bcd cd

I'm looking for the result to be:

ab abc bc ab abc abcd bc bcd cd

Just substrings that are in alphabetical order.

Answer 1

You're printing the substring whenever you find a pair of characters that are in order, not testing all characters in the substring.

You can use the all() function to test whether the whole substring meets the requirement.

s = 'abcabcd'
a = len(s)
for x in range(a):
    for y in range(x+2, a+1):
        if all(s[z] < s[z+1] for z in range(x, y-1)):
            print(s[x:y])