import re
from collections import defaultdict
def group_by_all_prefixes(s):
words = re.findall(r"[a-zA-Z]+", s.lower())
groups = defaultdict(list)
for w in words:
for i in range(1, len(w) + 1):
groups[w[:i]].append(w)
return dict(groups)
s = "The Lowly inhabitants of the lowland were surprised to see the lower branches of the trees."
groups = group_by_all_prefixes(s)
# Show only prefixes that appear in 2+ words
filtered = {p: ws for p, ws in groups.items() if len(ws) >= 2}
# Find the longest prefix
longest_prefix = max(filtered, key=len)
print("Longest shared prefix:")
print(f"{longest_prefix} | prefix_len={len(longest_prefix)} | group_count={len(filtered[longest_prefix])} | {filtered[longest_prefix]}")
'''
run:
Longest shared prefix:
lowl | prefix_len=4 | group_count=2 | ['lowly', 'lowland']
'''
