# re_del_non_alphanum.py

# re_del_non_alphanum.py

import re

# Sample string
text = "Example (123) 321 - okay - [456.789] - (abc) python [def] - 12345 - 67890"

# Correct regex pattern using alternations for each start/end pair
pattern = r'\([^a-zA-Z]*\)|\[[^a-zA-Z]*\]|-[^a-zA-Z]*(?:-|$)'

# Replace the matched substrings with an empty string
result = re.sub(pattern, '', text)

# Remove any extra spaces left by removals
result = re.sub(r'\s+', ' ', result).strip()

print(result)