ssl.SSLCertVerificationError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: certificate signature failure (_ssl.c:1108) code example
Example: ssl.SSLCertVerificationError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1091)
Once upon a time I stumbled with this issue. If you're using macOS go to Macintosh HD > Applications > Python3.6 folder (or whatever version of python you're using) > double click on "Install Certificates.command" file.