import re
str = """------------------
[' 3', ' 8', ' 1'][' 7', ' ', ' 5'][' 6', ' 4', ' 2']
------------------"""
print(re.findall(r"(?<=')\s*\d*(?=')", str))
aW1wb3J0IHJlCgpzdHIgPSAiIiItLS0tLS0tLS0tLS0tLS0tLS0KWycgMycsICcgOCcsICcgMSddWycgNycsICcgICcsICcgNSddWycgNicsICcgNCcsICcgMiddCi0tLS0tLS0tLS0tLS0tLS0tLSIiIgoKcHJpbnQocmUuZmluZGFsbChyIig/PD0nKVxzKlxkKig/PScpIiwgc3RyKSk=