pip install failed

[yangboz]

[y3.9 ,while executing pip install -r requirements.txt, it throws:

[15/41] Cythonizing pandas/_libs/reduction.pyx
      [end of output]
  
  note: This error originates from a subprocess, and is likely not a problem with pip.
error: metadata-generation-failed

× Encountered error while generating package metadata.
╰─> See above for output.

note: This is an issue with the package mentioned above, not pip.

``` any idea? thanks.