对于任何使用mechanize遇到这个问题的人，下面是如何将相同的技术应用到mechanize Browser实例:

br = mechanize.Browser()
context = ssl._create_unverified_context()
br.set_ca_data(context=context)

这里已经有很多答案了，但我们在一个非常具体的案例中遇到了这个问题，花了很多时间调查，所以再加一个。我们在下面的例子中看到:

在一个德比安式细长的码头集装箱里 默认Python 3.5.3 easy_install3 对于在Kubernetes集群中使用cert-manager注册的LetsEncrypt证书

pip3和openssl命令行都能够验证该证书，easy_install3能够成功验证其他LetsEncrypt证书。

解决办法是从源代码构建最新的Python(当时是3.7.3)。这里的说明很详细，很容易理解。

我在这里找到了这个

我找到了这个解决方案，在你的源文件开始插入这段代码:

import ssl

try:
   _create_unverified_https_context = ssl._create_unverified_context
except AttributeError:
    # Legacy Python that doesn't verify HTTPS certificates by default
    pass
else:
    # Handle target environment that doesn't support HTTPS verification
    ssl._create_default_https_context = _create_unverified_https_context

这段代码将撤销验证，这样就不会验证ssl证书。

我在Python 2.7.9中遇到了这个问题

以下是我所做的:

卸载Python 2.7.9 删除c:\Python27文件夹 下载了Python 2.7.18，这是今天最新发布的Python 2.7。 重新运行应用程序 它成功了!

不再有任何“[CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:581)”错误。

对于Linux Python3.6，这对我来说是可行的。

从命令行安装pyopenssl和certifi

sudo pip3 install -U pyopenssl
sudo pip3 install certifi

在我的python3脚本中，添加了verify='/usr/lib/python3.6/site-packages/certifi/cacert。Pem '是这样的:

import requests
from requests.auth import HTTPBasicAuth
import certifi

auth = HTTPBasicAuth('username', 'password')
body = {}

r = requests.post(url='https://your_url.com', data=body, auth=auth, verify='/usr/lib/python3.6/site-packages/certifi/cacert.pem')

The SSL: CERTIFICATE_VERIFY_FAILED error could also occur because an Intermediate Certificate is missing in the ca-certificates package on Linux. For example, in my case the intermediate certificate "DigiCert SHA2 Secure Server CA" was missing in the ca-certificates package even though the Firefox browser includes it. You can find out which certificate is missing by directly running the wget command on the URL causing this error. Then you can search for the corresponding link to the CRT file for this certificate from the official website (e.g. https://www.digicert.com/digicert-root-certificates.htm in my case) of the Certificate Authority. Now, to include the certificate that is missing in your case, you may run the below commands using your CRT file download link instead:

wget https://cacerts.digicert.com/DigiCertSHA2SecureServerCA.crt

mv DigiCertSHA2SecureServerCA.crt DigiCertSHA2SecureServerCA.der

openssl x509 -inform DER -outform PEM -in DigiCertSHA2SecureServerCA.der -out DigicertSHA2SecureServerCA.pem.crt

sudo mkdir /usr/share/ca-certificates/extra

sudo cp DigicertSHA2SecureServerCA.pem.crt /usr/share/ca-certificates/extra/

sudo dpkg-reconfigure ca-certificates

在此之后，您可以再次使用wget测试URL，也可以使用python urllib包进行测试。详情请参考:https://bugs.launchpad.net/ubuntu/+source/ca-certificates/+bug/1795242