Positive Lookahead (Password) in PY
Use positive lookahead `(?=...)` to require the password contain at least one digit and one uppercase letter.
Try it in the PY tester →Pattern
regexPY
^(?=.*\d)(?=.*[A-Z])[A-Za-z\d]{8,}$Python (re) code
pyPython
import re
pattern = re.compile(r"^(?=.*\d)(?=.*[A-Z])[A-Za-z\d]{8,}$")
input_text = "Password1"
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
(?=.*\d) is a zero-width assertion that requires the rest of the string to contain a digit somewhere. (?=.*[A-Z]) similarly requires an uppercase letter. Neither consumes characters. [A-Za-z\d]{8,}$ then matches the actual password content (≥8 alphanumerics). Lookaheads are supported in JS and Python; Go's RE2 does NOT support them.
Examples
Input
Password1Matches
Password1
Input
weakpassNo match
—Input
ALLCAPSNODIGITNo match
—