import re
rx = r"\b(?<!\w)((?:north|south)?(?:east|west)?)\b(?!\w)"
s = "The westerly barn is a room. The field is east of the barn. The stable is northeast of the field. The forest is northwest of the field."
print( re.findall(rx, s) )
aW1wb3J0IHJlCnJ4ID0gciJcYig/PCFcdykoKD86bm9ydGh8c291dGgpPyg/OmVhc3R8d2VzdCk/KVxiKD8hXHcpIgpzID0gIlRoZSB3ZXN0ZXJseSBiYXJuIGlzIGEgcm9vbS4gVGhlIGZpZWxkIGlzIGVhc3Qgb2YgdGhlIGJhcm4uICAgVGhlIHN0YWJsZSBpcyBub3J0aGVhc3Qgb2YgdGhlIGZpZWxkLiBUaGUgZm9yZXN0IGlzIG5vcnRod2VzdCBvZiB0aGUgZmllbGQuIgpwcmludCggcmUuZmluZGFsbChyeCwgcykgKSA=