pip install fail with SSL certificate verify failed (_ssl.c:833)

I have experienced similar issues when I am in a corporate network where a proxy is required for external network access. In this case, we'll have to tell pip the proxy:

pip --proxy=http://your.corporate.proxy.com  install pytesseract

Another possible cause is due to the pypi domain change. In this case, you can try the solution as below:

pip --index-url=http://pypi.python.org/simple/ --trusted-host pypi.python.org install pytesseract

Another similar case with an excellent answer: pip always fails ssl verification