Sentence Boundary in PY
Matches sentence boundaries (punctuation followed by whitespace and a capital letter).
Try it in the PY tester →Pattern
regexPY
[.!?]\s+(?=[A-Z]) (flags: g)Python (re) code
pyPython
import re
pattern = re.compile(r"[.!?]\s+(?=[A-Z])")
input_text = "Hello world. How are you? I'm fine!"
for m in pattern.finditer(input_text):
print(m.group(0))Stdlib `re` module — no third-party dependency. Works on Python 3.6+.
How the pattern works
`[.!?]` matches terminating punctuation. `\s+` matches whitespace. `(?=[A-Z])` is a lookahead for a capital letter (marks where the next sentence begins).
Examples
Input
Hello world. How are you? I'm fine!Matches
.?