python - 缓存条目反序列化失败，条目被忽略

Question

C:\Users\deypr>pip3 install sklearn

Collecting sklearn

  Cache entry deserialization failed, entry ignored

  Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: TLSV1_ALERT_ACCESS_DENIED] tlsv1 alert access denied (_ssl.c:777)'),)': /simple/sklearn/

  Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: TLSV1_ALERT_ACCESS_DENIED] tlsv1 alert access denied (_ssl.c:777)'),)': /simple/sklearn/

  Retrying (Retry(total=2, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: TLSV1_ALERT_ACCESS_DENIED] tlsv1 alert access denied (_ssl.c:777)'),)': /simple/sklearn/

  Retrying (Retry(total=1, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: TLSV1_ALERT_ACCESS_DENIED] tlsv1 alert access denied (_ssl.c:777)'),)': /simple/sklearn/

  Retrying (Retry(total=0, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: TLSV1_ALERT_ACCESS_DENIED] tlsv1 alert access denied (_ssl.c:777)'),)': /simple/sklearn/

  Could not fetch URL https://pypi.python.org/simple/sklearn/: There was a problem confirming the ssl certificate: HTTPSConnectionPool(host='pypi.python.org', port=443): Max retries exceeded with url: /simple/sklearn/ (Caused by SSLError(SSLError(1, '[SSL: TLSV1_ALERT_ACCESS_DENIED] tlsv1 alert access denied (_ssl.c:777)'),)) - skipping

 Could not find a version that satisfies the requirement sklearn (from versions: )
No matching distribution found for sklearn

每当尝试安装任何 python3 包时，我都会收到此错误。

1. 可能的原因是什么？

2. 如何解决？

Answer 1

关于问题标题中的错误/警告消息:

Cache entry deserialization failed, entry ignored

您可以通过删除 pip 缓存来修复它，例如在 Ubuntu 上:

rm -rf ~/.cache/pip