class_docstr: PCB (Part-based Convolutional Baseline), see https://arxiv.org/abs/1711.09349,
  Pyramidal Person Re-IDentification, see https://arxiv.org/abs/1810.12193
  
  Args:
      input_ch (int): Number of channels of the input feature.
      num_stripes (int): Number of sub-parts.
      used_levels (tuple): Whether the level is used, 1 means used.
      num_classes (int): Number of classes for identities, default 751 in
          Market-1501 dataset.
      last_conv_stride (int): Stride of the last conv.
      last_conv_dilation (int): Dilation of the last conv.
      num_conv_out_channels (int): Number of channels of conv feature.
code: def __init__(
      self,
      input_ch=2048,
      model_name="ResNet101",
      num_stripes=6,
      used_levels=(1, 1, 1, 1, 1, 1),
      num_classes=751,
      last_conv_stride=1,
      last_conv_dilation=1,
      num_conv_out_channels=128,
  ):
      super(PCBPyramid, self).__init__()
      self.num_stripes = num_stripes
      self.used_levels = used_levels
      self.num_classes = num_classes
  
      self.num_in_each_level = [
          i for i in range(self.num_stripes, 0, -1)
      ]
      self.num_branches = sum(self.num_in_each_level)
  
      assert model_name in [
          "ResNet50",
          "ResNet101",
      ], "Unsupported ReID arch: {}".format(model_name)
      self.base = eval(model_name)(
          lr_mult=0.1,
          last_conv_stride=last_conv_stride,
          last_conv_dilation=last_conv_dilation,
      )
      self.dropout_layer = nn.Dropout(p=0.2)
      (
          self.pyramid_conv_list0,
          self.pyramid_fc_list0,
      ) = self.basic_branch(num_conv_out_channels, input_ch)
  
file_path: PaddleDetection/ppdet/modeling/reid/pyramidal_embedding.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import paddle
  import paddle.nn
  import paddle.nn.functional
  from paddle.nn.initializer import Normal, Constant
  from paddle import ParamAttr
  from .resnet import ResNet50, ResNet101
  from ppdet.core.workspace import register
label_desc: Use image node_id 1 to create a new PCBPyramid object from inherited base classes: nn with example: obj = PCBPyramid(input_ch, model_name, num_stripes, used_levels, num_classes, last_conv_stride, last_conv_dilation, num_conv_out_channels)