First, there&#x27;s no reason to only associate &quot;Python&quot; with &quot;the language&quot;, it is an environment, ecosystem, etc. It&#x27;s not interesting to narrowly focus on the efficiency of the interpreter.<p>Second, it <i>is</i> an inherent feature of the design of CPython that its C API allows tight integration with external libraries in C. Cython does not just glue C and Python together, it does this in a way which makes the integration easier and safer than doing it by hand (e.g., generating correct reference counting code). All of this is a direct benefit of Python and its scientific ecosystem.