解决ModuleNotFoundError: No module named ‘absl‘报错

解决运行python train.py --epoch 100 --data data/ab.yaml --cfg yolov5s.yaml  --device '0'

的时候报错，如下：

Traceback (most recent call last):
  File "train.py", line 48, in <module>
    from utils.loggers.wandb.wandb_utils import check_wandb_resume
  File "/home/sxj/opencv_yolov5/yolov5_1/utils/loggers/__init__.py", line 12, in <module>
    from torch.utils.tensorboard import SummaryWriter
  File "/home/sxj/anaconda3/envs/yolo/lib/python3.7/site-packages/torch/utils/tensorboard/__init__.py", line 13, in <module>
    from .writer import FileWriter, SummaryWriter  # noqa: F401
  File "/home/sxj/anaconda3/envs/yolo/lib/python3.7/site-packages/torch/utils/tensorboard/writer.py", line 13, in <module>
    from tensorboard.summary.writer.event_file_writer import EventFileWriter
  File "/home/sxj/anaconda3/envs/yolo/lib/python3.7/site-packages/tensorboard/summary/__init__.py", line 33, in <module>
    from tensorboard.summary._output import DirectoryOutput  # noqa: F401
  File "/home/sxj/anaconda3/envs/yolo/lib/python3.7/site-packages/tensorboard/summary/_output.py", line 20, in <module>
    from tensorboard.util import tensor_util
  File "/home/sxj/anaconda3/envs/yolo/lib/python3.7/site-packages/tensorboard/util/tensor_util.py", line 20, in <module>
    from tensorboard.compat.tensorflow_stub import dtypes, compat, tensor_shape
  File "/home/sxj/anaconda3/envs/yolo/lib/python3.7/site-packages/tensorboard/compat/tensorflow_stub/__init__.py", line 25, in <module>
    from . import app  # noqa
  File "/home/sxj/anaconda3/envs/yolo/lib/python3.7/site-packages/tensorboard/compat/tensorflow_stub/app.py", line 21, in <module>
    from . import flags
  File "/home/sxj/anaconda3/envs/yolo/lib/python3.7/site-packages/tensorboard/compat/tensorflow_stub/flags.py", line 25, in <module>
    from absl.flags import *  # pylint: disable=wildcard-import
ModuleNotFoundError: No module named 'absl'

原因就是我前一段时间改过OpenCV的版本卸载过一些又下载过一些软件：可能因为某些软件版本问题，这个版本没有absl这个插件

我用(pip install absl下载不行）需要用conda下载（不清楚什么原理）

 conda install absl-py

接着运行：

python train.py --epoch 100 --data data/ab.yaml --cfg yolov5s.yaml  --device '0'

没有报错