def create_network()

in darknet.py [0:0]


    def create_network(self, blocks):
        models = nn.ModuleList()
    
        prev_filters = 3
        out_filters =[]
        conv_id = 0
        for block in blocks:
            if block['type'] == 'net':
                prev_filters = int(block['channels'])
                continue
            elif block['type'] == 'convolutional':
                conv_id = conv_id + 1
                batch_normalize = int(block['batch_normalize'])
                filters = int(block['filters'])
                kernel_size = int(block['size'])
                stride = int(block['stride'])
                is_pad = int(block['pad'])
                pad = (kernel_size-1)//2 if is_pad else 0
                activation = block['activation']
                model = nn.Sequential()
                if batch_normalize:
                    model.add_module('conv{0}'.format(conv_id), nn.Conv2d(prev_filters, filters, kernel_size, stride, pad, bias=False))
                    model.add_module('bn{0}'.format(conv_id), nn.BatchNorm2d(filters, eps=1e-4))
                    #model.add_module('bn{0}'.format(conv_id), BN2d(filters))
                else:
                    model.add_module('conv{0}'.format(conv_id), nn.Conv2d(prev_filters, filters, kernel_size, stride, pad))
                if activation == 'leaky':
                    model.add_module('leaky{0}'.format(conv_id), nn.LeakyReLU(0.1, inplace=True))
                elif activation == 'relu':
                    model.add_module('relu{0}'.format(conv_id), nn.ReLU(inplace=True))
                prev_filters = filters
                out_filters.append(prev_filters)
                models.append(model)
            elif block['type'] == 'maxpool':
                pool_size = int(block['size'])
                stride = int(block['stride'])
                if stride > 1:
                    model = nn.MaxPool2d(pool_size, stride)
                else:
                    model = MaxPoolStride1()
                out_filters.append(prev_filters)
                models.append(model)
            elif block['type'] == 'avgpool':
                model = GlobalAvgPool2d()
                out_filters.append(prev_filters)
                models.append(model)
            elif block['type'] == 'softmax':
                model = nn.Softmax()
                out_filters.append(prev_filters)
                models.append(model)
            elif block['type'] == 'cost':
                if block['_type'] == 'sse':
                    model = nn.MSELoss(size_average=True)
                elif block['_type'] == 'L1':
                    model = nn.L1Loss(size_average=True)
                elif block['_type'] == 'smooth':
                    model = nn.SmoothL1Loss(size_average=True)
                out_filters.append(1)
                models.append(model)
            elif block['type'] == 'reorg':
                stride = int(block['stride'])
                prev_filters = stride * stride * prev_filters
                out_filters.append(prev_filters)
                models.append(Reorg(stride))
            elif block['type'] == 'route':
                layers = block['layers'].split(',')
                ind = len(models)
                layers = [int(i) if int(i) > 0 else int(i)+ind for i in layers]
                if len(layers) == 1:
                    prev_filters = out_filters[layers[0]]
                elif len(layers) == 2:
                    assert(layers[0] == ind - 1)
                    prev_filters = out_filters[layers[0]] + out_filters[layers[1]]
                out_filters.append(prev_filters)
                models.append(EmptyModule())
            elif block['type'] == 'shortcut':
                ind = len(models)
                prev_filters = out_filters[ind-1]
                out_filters.append(prev_filters)
                models.append(EmptyModule())
            elif block['type'] == 'connected':
                filters = int(block['output'])
                if block['activation'] == 'linear':
                    model = nn.Linear(prev_filters, filters)
                elif block['activation'] == 'leaky':
                    model = nn.Sequential(
                               nn.Linear(prev_filters, filters),
                               nn.LeakyReLU(0.1, inplace=True))
                elif block['activation'] == 'relu':
                    model = nn.Sequential(
                               nn.Linear(prev_filters, filters),
                               nn.ReLU(inplace=True))
                prev_filters = filters
                out_filters.append(prev_filters)
                models.append(model)
            elif block['type'] == 'region':
                loss = RegionLoss()
                anchors = block['anchors'].split(',')
                if anchors == ['']:
                    loss.anchors = []
                else:
                    loss.anchors = [float(i) for i in anchors]
                loss.num_classes = int(block['classes'])
                loss.num_anchors = int(block['num'])
                loss.anchor_step = len(loss.anchors)//loss.num_anchors
                loss.object_scale = float(block['object_scale'])
                loss.noobject_scale = float(block['noobject_scale'])
                loss.class_scale = float(block['class_scale'])
                loss.coord_scale = float(block['coord_scale'])
                out_filters.append(prev_filters)
                models.append(loss)
            else:
                print('unknown type %s' % (block['type']))
    
        return models