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[英]Change python2 to python3 when using the terminal for jupyter notebook
[英]code change - using python2 changing to python3
这是O'Reily Twisted Network编程基础知识手册中的一部分示例代码。 "h = HeadlineRetriever()
行引起了问题。错误日志显示未定义“ HeadlineRetriever”。这是由于py3中的更改引起的吗?如何解决此问题?
尝试过: d.addCallbacks(printData, printError)
h = HeadlineRetrieveer()
,然后d.addCallbacks(printData, printError)
无法识别参数。
from twisted.internet import reactor, defer
class HeadlineRetriever(object):
def processHeadline(self, headline):
if len(headline) > 50:
self.d.errback(
b"The headline ''%s'' is too long!" % (headline,))
else:
self.d.callback(headline)
def _toHTML(self, result):
return "<h1>%s</h1>" % (result,)
def getHeadline(self, input):
self.d = defer.Deferred()
reactor.callLater(1, self.processHeadline, input)
self.d.addCallback(self._toHTML)
return self.d
def printData(result):
print(result)
reactor.stop()
def printError(failure):
print(failure)
reactor.stop()
h = HeadlineRetriever()
d = h.getHeadline("Breaking News: Twisted Takes Us to the Moon!")
d.addCallbacks(printData, printError)
reactor.run()
错误日志:追溯(最近一次呼叫最近):
File "C:/Users/jessica/Twisted/3.4asynchronousHeadlineRetriever.py", line 3, in <module>
class HeadlineRetriever(object):
File "C:/Users/jessica/Twisted/3.4asynchronousHeadlineRetriever.py", line 28, in HeadlineRetriever
h = HeadlineRetriever()
NameError: name 'HeadlineRetriever' is not defined
我认为在您定义h时以及在类本身中会出现识别错误
from twisted.internet import reactor, defer
class HeadlineRetriever(object):
def processHeadline(self, headline):
if len(headline) > 50:
self.d.errback(
b"The headline ''%s'' is too long!" % (headline,))
else:
self.d.callback(headline)
def _toHTML(self, result):
return "<h1>%s</h1>" % (result,)
def getHeadline(self, input):
self.d = defer.Deferred()
reactor.callLater(1, self.processHeadline, input)
self.d.addCallback(self._toHTML)
return self.d
def printData(result):
print(result)
reactor.stop()
def printError(failure):
print(failure)
reactor.stop()
h = HeadlineRetriever()
d = h.getHeadline("Breaking News: Twisted Takes Us to the Moon!")
d.addCallbacks(printData, printError)
reactor.run()
这应该工作
你好吗?
也许您缺少__init__
方法,也请保持代码在左边界缩进,如果不是,则可能会导致您的代码有问题。
尝试添加:
def __init__(self):
pass
看看是否可行,然后更新我。
干杯!
from twisted.internet import reactor, defer
class HeadlineRetriever(object):
def processHeadline(self, headline):
if len(headline) > 50:
self.d.errback(
b"The headline ''%s'' is too long!" % (headline,))
else:
self.d.callback(headline)
def _toHTML(self, result):
return "<h1>%s</h1>" % (result,)
def getHeadline(self, input):
self.d = defer.Deferred()
reactor.callLater(1, self.processHeadline, input)
self.d.addCallback(self._toHTML)
return self.d
def printData(self, result):
print(result)
reactor.stop()
def printError(self, failure):
print(failure)
reactor.stop()
h = HeadlineRetriever()
d = h.getHeadline("Breaking News: Twisted Takes Us to the Moon!")
d.addCallbacks(h.printData, h.printError)
reactor.run()
printError和print数据函数需要自己作为第一个参数并在调用中。 d.adCallbacks(printData, printError)
d.addcallbacks(h.printData, h.printError)
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