Question

我得到了：

TypeError：*：＆＃39; int＆＃39;不支持的操作数类型和＆＃39; NoneType

析因程序中的

错误。任何人都可以帮帮我..

def factorial(n):
     if n == 0:
         return 1
     if n > 1:
         return n*factorial(n -1)

print(factorial (5))

Answer 1

从factorial(2)开始时会发生什么，以及n == 1时函数会返回什么？

如果没有命中return语句，则该函数隐式返回None。

Answer 2

将java.lang.IllegalAccessError: tried to access method com.google.gson.Gson.newJsonWriter(Ljava/io/Writer;)Lcom/google/gson/stream/JsonWriter; from class retrofit2.converter.gson.GsonRequestBodyConverter at retrofit2.converter.gson.GsonRequestBodyConverter.convert(GsonRequestBodyConverter.java:45) at retrofit2.converter.gson.GsonRequestBodyConverter.convert(GsonRequestBodyConverter.java:30) at retrofit2.ParameterHandler$Body.apply(ParameterHandler.java:312) at retrofit2.ServiceMethod.toRequest(ServiceMethod.java:110) at retrofit2.OkHttpCall.createRawCall(OkHttpCall.java:178) at retrofit2.OkHttpCall.execute(OkHttpCall.java:162) at com.xxxxxx.web.controller.UserController.exchangeAccessToken(UserController.java:2551) at com.xxxxxx.web.controller.UserController.plaidtoken(UserController.java:2645) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:215) at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132) at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:745) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:685) at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:919) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:851) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:953) at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:855) at javax.servlet.http.HttpServlet.service(HttpServlet.java:661) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:829) at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:106) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80) at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:624) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:341) at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:799) at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:861) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1455) at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745)更改为n > 1，因为在递归中没有n = 1的情况。

Answer 3

也许n == None检查一下

if n == None:
    print("n == None")

如果您确定它不是null，则将其转换为int：n = int(n)

编辑无，因为我在python中编码

，所以没有长时间

为什么我收到此错误？我不明白什么是typerror

3 个答案: