import re
s = "test1 this is a sample subscript o₁"
print(re.findall(r'\b[a-zA-Z]{2,}\b', s))
print(re.findall(r'\b[^\W\d_]{2,}\b', s, re.ASCII))
aW1wb3J0IHJlCnMgPSAidGVzdDEgdGhpcyBpcyBhIHNhbXBsZSBzdWJzY3JpcHQgb+KCgSIKcHJpbnQocmUuZmluZGFsbChyJ1xiW2EtekEtWl17Mix9XGInLCBzKSkKcHJpbnQocmUuZmluZGFsbChyJ1xiW15cV1xkX117Mix9XGInLCBzLCByZS5BU0NJSSkp