I got a very strange issue with my Python3.7.3.
I use ssl module with urllin.request , when I visit some https website my script always die .so I got this :

*******************************************************************
Python 3.7.3 (default, Dec 26 2020, 06:35:45)
[GCC 6.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import ssl                                                                 >>> ssl.OPENSSL_VERSION
'LibreSSL 3.1.1'
>>> ssl.SSLContext()
Killed
*******************************************************************

Just "Killed" , no more infomation . 
How to check this problem ?

3.7.3 is an old release of an old version.  It has already been patched a few times.  If you cannot upgrade to at least the last bugfix release of 3.7, you are somewhat on your own.

The word 'Killed' in not in the ssl module, so I presume it comes from the LibreSSL, which on your system is what is imported as _ssl.  On Win 10, 'import ssl' prints nothing (normal for most imports) and ssl.SSLContext returns an instance of class SSLContext.

You question would be better asked on a help forum, such as python-list or stackoverflow.

What exactly happens when you try to instantiate an SSLContext() object? Does it just print the string "Killed" or does the process stop and segfault immediately?

If it's a segfault then it is likely caused by an incompatibility between recent LibreSSL and old Python 3.7.3. Can you switch to OpenSSL? LibreSSL isn't well supported.

The op hasn't replied in over 3 months. I'm closing the bug as staled.