使用pip在python中下载flask包时出错

Error in downloading flask package in python using pip

我正在尝试在python3中安装flask。在给出命令python -m pip install flask时，我收到错误

Retrying (Retry(total=4, connect=None, read=None, redirect=None,
status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL:
CERTIFICATE_VERIFY_FAILED] certificate verify failed
(_ssl.c:748)'),)': /simple/flask/ Retrying (Retry(total=3,
connect=None, read=None, redirect=None, status=None)) after connection
broken by 'SSLError(SSLError(1, '[SSL: CERTIFICATE_VERIFY_FAILED]
certificate verify failed (_ssl.c:748)'),)': /simple/flask/ Retrying
(Retry(total=2, connect=None, read=None, redirect=None, status=None))
after connection broken by 'SSLError(SSLError(1, '[SSL:
CERTIFICATE_VERIFY_FAILED] certificate verify failed
(_ssl.c:748)'),)': /simple/flask/ Retrying (Retry(total=1,
connect=None, read=None, redirect=None, status=None)) after connection
broken by 'SSLError(SSLError(1, '[SSL: CERTIFICATE_VERIFY_FAILED]
certificate verify failed (_ssl.c:748)'),)': /simple/flask/ Retrying
(Retry(total=0, connect=None, read=None, redirect=None, status=None))
after connection broken by 'SSLError(SSLError(1, '[SSL:
CERTIFICATE_VERIFY_FAILED] certificate verify failed
(_ssl.c:748)'),)': /simple/flask/ Could not fetch URL
https://pypi.python.org/simple/flask/: There was a problem confirming
the ssl certificate: HTTPSConnectionPool(host='pypi.python.org',
port=443): Max retries exceeded with url: /simple/flask/ (Caused by
SSLError(SSLError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate
verify failed (_ssl.c:748)'),)) - skipping Could not find a version
that satisfies the requirement flask (from versions: ) No matching
distribution found for flask