import re
regex = r"\w+,\s*f\s*\.\s*\d\s*\d\s*-\s*\d\s*\d\s*-\s*\d\s*\d\s*\d\s*\d"
test_str = ("Smith, John,\n\n"
"f. 25-12-1990\n\n"
"or only first part of below:\n\n"
"Smith, John, f. 25-12-\n\n"
"1990\n\n"
"Smith, John, f. 25-\n\n"
"12-1990")
matches = re.findall(regex, test_str)
print(matches)
aW1wb3J0IHJlCgpyZWdleCA9IHIiXHcrLFxzKmZccypcLlxzKlxkXHMqXGRccyotXHMqXGRccypcZFxzKi1ccypcZFxzKlxkXHMqXGRccypcZCIKCnRlc3Rfc3RyID0gKCJTbWl0aCwgSm9obixcblxuIgoJImYuIDI1LTEyLTE5OTBcblxuIgoJIm9yIG9ubHkgZmlyc3QgcGFydCBvZiBiZWxvdzpcblxuIgoJIlNtaXRoLCBKb2huLCBmLiAyNS0xMi1cblxuIgoJIjE5OTBcblxuIgoJIlNtaXRoLCBKb2huLCBmLiAyNS1cblxuIgoJIjEyLTE5OTAiKQoKbWF0Y2hlcyA9IHJlLmZpbmRhbGwocmVnZXgsIHRlc3Rfc3RyKQpwcmludChtYXRjaGVzKQ==