问ImportError:无法从“charset_normalizer.constant”导入名称“COMMON_SAFE_ASCII_CHARACTERS”

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Traceback (most recent call last):
  File "g:\mydrive\ \pdftotext_pdfminer.py", line 3, in <module>
    from pdfminer.pdfinterp import PDFResourceManager, PDFPageInterpreter
  File "C:\Users\ \anaconda3\envs\ \lib\site-packages\pdfminer\pdfinterp.py", line 7, in <module> 
    from .cmapdb import CMap
  File "C:\Users\ \anaconda3\envs\ \lib\site-packages\pdfminer\encodingdb.py", line 7, in <module>
    from .psparser import PSLiteral
  File "C:\Users\ \anaconda3\envs\ \lib\site-packages\pdfminer\psparser.py", line 22, in <module>
    from .utils import choplist
  File "C:\Users\ \anaconda3\envs\ \lib\site-packages\pdfminer\utils.py", line 31, in <module>
    import charset_normalizer  # For str encoding detection
  File "C:\Users\ \anaconda3\envs\ \lib\site-packages\charset_normalizer\__init__.py", line 23, in <module>
    from charset_normalizer.api import from_fp, from_path, from_bytes, normalize
  File "C:\Users\ \anaconda3\envs\ \lib\site-packages\charset_normalizer\api.py", line 10, in <module>
    from charset_normalizer.md import mess_ratio
  File "charset_normalizer\md.py", line 5, in <module>
ImportError: cannot import name 'COMMON_SAFE_ASCII_CHARACTERS' from 'charset_normalizer.constant' (C:\Users\ \anaconda3\envs\ \lib\site-packages\charset_normalizer\constant.py)