PCAP Modules and Packages Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  Import http.server, define handler class, create HTTPServer instance, call serve_forever()

  Why this is correct

  Correct order: First import the module, then define a handler class that inherits from BaseHTTPRequestHandler, then create an instance of HTTPServer with the server address and handler class, and finally call serve_forever() to start the server.

• ✗

  Define handler class, import http.server, create HTTPServer instance, call serve_forever()

  Why it's wrong here

  Defining the handler class before importing http.server fails because Python resolves base classes at class definition time. Since http.server is not yet in the module's namespace, the expression http.server.BaseHTTPRequestHandler raises NameError. The import statement must execute first to make the module's attributes available. Thus, starting with the class definition is invalid.

• ✗

  Import http.server, create HTTPServer instance, define handler class, call serve_forever()

  Why it's wrong here

  Creating the HTTPServer instance before defining the handler class is invalid because the constructor's second argument must be the actual handler class (e.g., a subclass of BaseHTTPRequestHandler). At that point, the name for the handler class is either undefined (NameError) or, if a placeholder was used, the server would be bound to the wrong class and fail on every request. The handler class must be fully defined first so it can be passed as a reference and stored by the server for later per-request instantiation.

• ✗

  Import http.server, define handler class, call serve_forever(), create HTTPServer instance

  Why it's wrong here

  Calling serve_forever() before constructing the HTTPServer object is a logical and runtime error: a method call requires an existing instance. Since no instance has been created, the call either refers to an unbound name (NameError) or, in some contexts, an attribute lookup on None (AttributeError). The server's main loop must be started on an already-bound and configured server object, so instantiation must precede the serve_forever() call.

Go deeper

Related to this question