Detectron 框架使用出现错误yaml.constructor.ConstructorError: could not determine a constructor for the tag

错误yaml.constructor.ConstructorError: could not determine a constructor for the tag

错误提示：

Traceback (most recent call last):
  File "tools/train_net.py", line 133, in <module>
    main()
  File "tools/train_net.py", line 98, in main
    if args.cfg_file is not None:
  File "/data/yang/detectron/detectron/utils/train.py", line 58, in train_model
    setup_model_for_training(model, weights_file, output_dir)
  File "/data/yang/detectron/detectron/utils/train.py", line 174, in setup_model_for_training
    nu.initialize_gpu_from_weights_file(model, weights_file, gpu_id=0)
  File "/data/yang/detectron/detectron/utils/net.py", line 65, in initialize_gpu_from_weights_file
    saved_cfg = load_cfg(src_blobs['cfg'])
  File "/data/yang/detectron/detectron/core/config.py", line 1147, in load_cfg
    return envu.yaml_load(cfg_to_load)
  File "/home/ec2-user/anaconda3/envs/pytorch_p36/lib/python3.6/site-packages/yaml/__init__.py", line 114, in load
    return loader.get_single_data()
  File "/home/ec2-user/anaconda3/envs/pytorch_p36/lib/python3.6/site-packages/yaml/constructor.py", line 51, in get_single_data
    return self.construct_document(node)
  File "/home/ec2-user/anaconda3/envs/pytorch_p36/lib/python3.6/site-packages/yaml/constructor.py", line 55, in construct_document
    data = self.construct_object(node)
  File "/home/ec2-user/anaconda3/envs/pytorch_p36/lib/python3.6/site-packages/yaml/constructor.py", line 102, in construct_object
    data = constructor(self, tag_suffix, node)
  File "/home/ec2-user/anaconda3/envs/pytorch_p36/lib/python3.6/site-packages/yaml/constructor.py", line 659, in construct_python_object_new
    return self.construct_python_object_apply(suffix, node, newobj=True)
  File "/home/ec2-user/anaconda3/envs/pytorch_p36/lib/python3.6/site-packages/yaml/constructor.py", line 642, in construct_python_object_apply
    value = self.construct_mapping(node, deep=True)
  File "/home/ec2-user/anaconda3/envs/pytorch_p36/lib/python3.6/site-packages/yaml/constructor.py", line 218, in construct_mapping
    return super().construct_mapping(node, deep=deep)
  File "/home/ec2-user/anaconda3/envs/pytorch_p36/lib/python3.6/site-packages/yaml/constructor.py", line 143, in construct_mapping
    value = self.construct_object(value_node, deep=deep)
  File "/home/ec2-user/anaconda3/envs/pytorch_p36/lib/python3.6/site-packages/yaml/constructor.py", line 107, in construct_object
    for dummy in generator:
  File "/home/ec2-user/anaconda3/envs/pytorch_p36/lib/python3.6/site-packages/yaml/constructor.py", line 413, in construct_yaml_map
    value = self.construct_mapping(node)
  File "/home/ec2-user/anaconda3/envs/pytorch_p36/lib/python3.6/site-packages/yaml/constructor.py", line 218, in construct_mapping
    return super().construct_mapping(node, deep=deep)
  File "/home/ec2-user/anaconda3/envs/pytorch_p36/lib/python3.6/site-packages/yaml/constructor.py", line 143, in construct_mapping
    value = self.construct_object(value_node, deep=deep)
  File "/home/ec2-user/anaconda3/envs/pytorch_p36/lib/python3.6/site-packages/yaml/constructor.py", line 100, in construct_object
    data = constructor(self, node)
  File "/home/ec2-user/anaconda3/envs/pytorch_p36/lib/python3.6/site-packages/yaml/constructor.py", line 429, in construct_undefined
    node.start_mark)
yaml.constructor.ConstructorError: could not determine a constructor for the tag 'tag:yaml.org,2002:python/object/apply:numpy.core.multiarray.scalar'
  in "<unicode string>", line 3, column 20:
      BBOX_XFORM_CLIP: !!python/object/apply:numpy.core ... 

错误原因分析：

pyyaml的版本不匹配造成的。

解决方法：

（1）卸载之前的版本

conda list
conda remove pyyaml
conda remove yaml

（2）安装此版本的yaml

pip install pyyaml==4.2b2

至此问题完美解决！！！

参考链接：

Detectron 框架安装与使用！