Question

我使用以下侦听器来侦听特定模式。我希望在发送给它的数据中找到“hello”。流程方法每秒调用多次，因此无法保存全部在不断增长的列表中处理的数据。有更好的方法吗？

class Listener:
    def __init__(self, data_to_catch):
        self.data_to_catch = data_to_catch
        self.length_of_data_to_catch = len(data_to_catch)
        self.previous_data = ""
        self.found = False

    def process(self, data):
        if self.found:
            return

        self.previous_data = self.previous_data + data
        if not self.data_to_catch in self.previous_data:
            # see if some of the data to catch has arrived, if so keep it                
            for i in reversed(range(min(self.length_of_data_to_catch,len(self.previous_data)))):
                if self.data_to_catch[:i+1] == self.previous_data[-i-1:]:
                    return
            else:
                self.previous_data = ""
                return

        self.found = True
        print("found!")

l = Listener("hello")
l.process("he")
l.process("llh")
l.process("e")
l.process("ll")
l.process("he")
l.process("llohe")

Answer 1

也许是这样的：

class Listener:
    def __init__(self, data_to_catch):
        self.data_to_catch = data_to_catch
        self.data = ""
        self.found = False
        self.pos = 0

    def process(self, data):
        if self.found:
            return

        self.data += data
        self.found = self.data_to_catch in self.data[self.pos:]
        self.pos = max(0, len(self.data) - len(self.data_to_catch))

        if self.found:
            print "found!"

l = Listener("hello")
l.process("he")
l.process("llh")
l.process("e")
l.process("ll")
l.process("he")
l.process("llohe")

虽然你确实说过（我最初错过了），但你想保持self.data的长度很小。在这种情况下，您可以执行以下操作：

    def process(self, data):
        if self.found:
            return

        self.data += data
        self.found = self.data_to_catch in self.data

        pos = max(0, len(self.data) - len(self.data_to_catch))
        self.data = self.data[pos:]

        if self.found:
            print "found!"

倾听特定的模式

1 个答案: