python: Fix NameError if asyncio is not available

python/nghttp2.pyx

@@ -250,7 +250,7 @@ try:
     import datetime
     import time
 except ImportError:
-    pass
+    asyncio = None
 
 cdef _get_stream_user_data(cnghttp2.nghttp2_session *session,
                            int32_t stream_id):
@@ -659,7 +659,9 @@ cdef class _HTTP2SessionCore:
                           datestr, method, path, handler.status,
                           'P' if handler.pushed else '-'))
 
-class BaseRequestHandler:
+if asyncio:
+
+    class BaseRequestHandler:
 
         """HTTP/2 request (stream) handler base class.
 
@@ -737,8 +739,8 @@ class BaseRequestHandler:
 
         def on_data(self, data):
 
-        '''Called when a chunk of request body is arrived. This method will be
-        called multiple times until all data are received.
+            '''Called when a chunk of request body is arrived. This method
+            will be called multiple times until all data are received.
 
             '''
             pass
@@ -786,12 +788,14 @@ class BaseRequestHandler:
         def push(self, path, method='GET', request_headers=None,
                  status=200, headers=None, body=None):
 
-        '''Push a resource. The path is a path portion of request URI for this
-        resource. The method is a method to access this resource. The
-        request_headers is additional request headers to access this
-        resource. The :scheme, :method, :authority and :path are
-        appended by the library. The :scheme and :authority are
-        inherited from the request (not request_headers parameter).
+            '''Push a resource. The path is a path portion of request URI
+            for this
+            resource. The method is a method to access this
+            resource. The request_headers is additional request
+            headers to access this resource. The :scheme, :method,
+            :authority and :path are appended by the library. The
+            :scheme and :authority are inherited from the request (not
+            request_headers parameter).
 
             The status is HTTP status code. The headers is additional
             response headers. The :status header field is appended by the
@@ -845,7 +849,8 @@ class BaseRequestHandler:
                 headers = []
 
             self.response_headers = _encode_headers(headers)
-        self.response_headers.append((b':status', str(status).encode('utf-8')))
+            self.response_headers.append((b':status', str(status)\
+                                          .encode('utf-8')))
 
             self.response_body = body
 
@@ -859,15 +864,15 @@ class BaseRequestHandler:
             elif isinstance(body, io.IOBase):
                 return body
             else:
-            raise Exception(('body must be None or instance of str or bytes '
-                             'or io.IOBase'))
+                raise Exception(('body must be None or instance of str or '
+                                 'bytes or io.IOBase'))
 
-def _encode_headers(headers):
+    def _encode_headers(headers):
         return [(k if isinstance(k, bytes) else k.encode('utf-8'),
                  v if isinstance(v, bytes) else v.encode('utf-8')) \
                 for k, v in headers]
 
-class _HTTP2Session(asyncio.Protocol):
+    class _HTTP2Session(asyncio.Protocol):
 
         def __init__(self, RequestHandlerClass):
             asyncio.Protocol.__init__(self)
@@ -897,7 +902,8 @@ class _HTTP2Session(asyncio.Protocol):
                 self.connection_header = self.connection_header[nread:]
                 if len(self.connection_header) == 0:
                     try:
-                    self.http2 = _HTTP2SessionCore(self.transport,
+                        self.http2 = _HTTP2SessionCore\
+                                     (self.transport,
                                       self.RequestHandlerClass)
                     except Exception as err:
                         sys.stderr.write(traceback.format_exc())
@@ -926,7 +932,7 @@ class _HTTP2Session(asyncio.Protocol):
                 self.transport.close()
                 return
 
-class HTTP2Server:
+    class HTTP2Server:
 
         '''HTTP/2 server.