Question

It s difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center.

Closed 11 years ago.

我利用以下听众聆听了一种特殊模式。我期望在送交的数据中找到“hello”。这一过程方法被多次称为二次,因此在保存一个不断增加的清单中处理的数据方面没有任何想法。这样做是否有不清的途径?

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

也许像这样:

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(我最初错过),但你希望保留<代码>的长度。在这种情况下,你可以做如下事情:

    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!"

友情链接