From the documentation:

requests can also ignore verifying the SSL certificate if you set verify to False.

>>> requests.get('https://kennethreitz.com', verify=False)
<Response [200]>

If you're using a third-party module and want to disable the checks, here's a context manager that monkey patches requests and changes it so that verify=False is the default and suppresses the warning.

import warnings
import contextlib

import requests
from urllib3.exceptions import InsecureRequestWarning

old_merge_environment_settings = requests.Session.merge_environment_settings

@contextlib.contextmanager
def no_ssl_verification():
    opened_adapters = set()

    def merge_environment_settings(self, url, proxies, stream, verify, cert):
        # Verification happens only once per connection so we need to close
        # all the opened adapters once we're done. Otherwise, the effects of
        # verify=False persist beyond the end of this context manager.
        opened_adapters.add(self.get_adapter(url))

        settings = old_merge_environment_settings(self, url, proxies, stream, verify, cert)
        settings['verify'] = False

        return settings

    requests.Session.merge_environment_settings = merge_environment_settings

    try:
        with warnings.catch_warnings():
            warnings.simplefilter('ignore', InsecureRequestWarning)
            yield
    finally:
        requests.Session.merge_environment_settings = old_merge_environment_settings

        for adapter in opened_adapters:
            try:
                adapter.close()
            except:
                pass

Here's how you use it:

with no_ssl_verification():
    requests.get('https://wrong.host.badssl.example/')
    print('It works')

    requests.get('https://wrong.host.badssl.example/', verify=True)
    print('Even if you try to force it to')

requests.get('https://wrong.host.badssl.example/', verify=False)
print('It resets back')

session = requests.Session()
session.verify = True

with no_ssl_verification():
    session.get('https://wrong.host.badssl.example/', verify=True)
    print('Works even here')

try:
    requests.get('https://wrong.host.badssl.example/')
except requests.exceptions.SSLError:
    print('It breaks')

try:
    session.get('https://wrong.host.badssl.example/')
except requests.exceptions.SSLError:
    print('It breaks here again')

Note that this code closes all open adapters that handled a patched request once you leave the context manager. This is because requests maintains a per-session connection pool and certificate validation happens only once per connection so unexpected things like this will happen:

>>> import requests
>>> session = requests.Session()
>>> session.get('https://wrong.host.badssl.example/', verify=False)
/usr/local/lib/python3.7/site-packages/urllib3/connectionpool.py:857: InsecureRequestWarning: Unverified HTTPS request is being made. Adding certificate verification is strongly advised. See: https://urllib3.readthedocs.io/en/latest/advanced-usage.html#ssl-warnings
  InsecureRequestWarning)
<Response [200]>
>>> session.get('https://wrong.host.badssl.example/', verify=True)
/usr/local/lib/python3.7/site-packages/urllib3/connectionpool.py:857: InsecureRequestWarning: Unverified HTTPS request is being made. Adding certificate verification is strongly advised. See: https://urllib3.readthedocs.io/en/latest/advanced-usage.html#ssl-warnings
  InsecureRequestWarning)
<Response [200]>

The problem you are having is caused by an untrusted SSL certificate.

Like dirk mentioned in a previous comment, the quickest fix is setting verify=False:

requests.get('https://example.com', verify=False)

Please note that this will cause the certificate not to be verified. This will expose your application to security risks, such as man-in-the-middle attacks.

Of course, apply judgment. As mentioned in the comments, this may be acceptable for quick/throwaway applications/scripts, but this should really not go to production software.

If just skipping the certificate check is not acceptable in your particular context, consider the following options, your best option is to set the verify parameter to a string that is the path of the .pem file of the certificate (which you should obtain by some sort of secure means).

So, as of version 2.0, the verify parameter accepts the following values, with their respective semantics:

• True: causes the certificate to validated against the library's own trusted certificate authorities (Note: you can see which root certificates (RCs) Requests uses via the Certifi library, a trust database of RCs extracted from Requests: Certifi - Trust Database for Humans).

• False: bypasses certificate validation completely.

• Path to a CA_BUNDLE file for Requests to use to validate the certificates.

Source: Requests - SSL Cert Verification

Also take a look at the cert parameter on the same page.