Regex_match.py

def match(self, s: str) -> bool:
    current_nodes = { 0 }
    self.expand_selection(current_nodes)
    for c in s:
        next_nodes = set()
        for s in current_nodes:
            if s < len(self.nodes):
                if self.nodes[s] == c or self.nodes[s] == '.':
                    next_nodes.add(s+1)
                    if self.stars[s]:
                        next_nodes.add(s)
        self.expand_selection(next_nodes)
        current_nodes = next_nodes
        if not current_nodes:
            return False

    last_node = max(current_nodes)
    return len(self.nodes) == last_node