[Python] Python `pip` on Windows - SSL: CERTIFICATE_VERIFY_FAILED

I'm working with Windows and since two days ago, I'm getting the following error:

ERROR: Could not install packages due to an OSError: HTTPSConnectionPool(host='f
iles.pythonhosted.org', port=443): Max retries exceeded with url: /packages/da/6
d/1235da14daddaa6e47f74ba0c255358f0ce7a6ee05da8bf8eb49161aa6b5/pandas-1.5.3-cp31
1-cp311-win_amd64.whl (Caused by SSLError(SSLCertVerificationError(1, '[SSL: CER
TIFICATE_VERIFY_FAILED] certificate verify failed: self signed certificate (_ssl
.c:992)')))


I get the error working with the python installed on my pc also into the different virtual environments. I tried it on Python 3.10 and 3.9 and both get it.

To solve it I tried the following solutions but neither of them worked:

This error occurs when the SSL certificate verification fails during a package installation using pip in Python on a Windows system. To fix this error, you can follow the steps given below:
Download the cacert.pem file from the official cURL website (https://curl.se/docs/caextract.html) and save it in a suitable location on your computer.

Set the SSL_CERT_FILE environment variable to the path of the "cacert.pem" file. You can do this by opening the Command Prompt and running the following command:

setx SSL_CERT_FILE "C:\path\to\cacert.pem"


Make sure to replace C:\path\to\cacert.pem with the actual path where you saved the "cacert.pem" file.

Close and reopen the Command Prompt to ensure that the environment variable is set correctly.

Try running the pip install command again.

This should resolve the error and allow you to install packages using pip on your Windows system.

Upgrade pip to the latest version using the following command:
python -m pip install --upgrade pip


Add the --trusted-host pypi.org --trusted-host files.pythonhosted.org option to your pip install command to instruct pip to trust the SSL certificates of these domains. For example:

pip install <package-name> --trusted-host pypi.org --trusted-host files.pythonhosted.org


If the above steps did not work, you can try updating the certifi package using the following command:

pip install --upgrade certifi


This will update the CA certificates that are used by Python to verify SSL connections.

If you are still facing the issue, you can try disabling SSL verification by adding the --trusted-host and --no-verify options to your pip install command:

pip install <package-name> --trusted-host pypi.org --trusted-host files.pythonhosted.org --no-verify


However, this is not recommended as it can pose a security risk.
​

As I mentioned, neither solution fixed the error. What is wrong with the SSL certificate?

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