<story><title>Proposal to Merge Pyston with Cpython</title><url>https://discuss.python.org/t/contributing-the-pyston-jit/24195</url></story><parent_chain><item><author>martopix</author><text>Can anyone that understands these things (i.e. not me, a meek python end user) explain this in simpler terms?&lt;p&gt;I checked th Pyston website, it essentially says it makes your code faster and nothing about what&amp;#x27;s the catch and how it magically works.</text></item></parent_chain><comment><author>junon</author><text>Let&amp;#x27;s assume you speak English - and more importantly, not Chinese.&lt;p&gt;Now, you need to have a conversation with someone who &lt;i&gt;only&lt;/i&gt; speaks Chinese. How do you do that? Well, you use an interpreter. They listen to what you say, and translate it to Chinese and speak on your behalf.&lt;p&gt;If you never had any interest in learning Chinese, this would be sufficient. Your conversation rate would be slow but it would get the job done.&lt;p&gt;Let&amp;#x27;s say there&amp;#x27;s an intense line of yes-or-no questioning, though. You need to say &amp;quot;yes&amp;quot; or &amp;quot;no&amp;quot; often, and decide that maybe learning the equivalent Chinese words or phrases would cut out the middleman, thus speeding up conversation in some cases.&lt;p&gt;This is what a JIT does, just replace English with Python&amp;#x27;s bytecode, and Chinese with your host CPU&amp;#x27;s architecture (e.g. x86 or ARM). The &amp;quot;when&amp;quot; of JITing code varies across implementations and approaches but the concept remains the same. Oftentimes the JIT runtime will translate just the hot codepaths.&lt;p&gt;If a compiler - e.g. one that compiles C code - is &amp;quot;ahead of time&amp;quot;, then a runtime that compiles on the fly does so &amp;quot;just in time&amp;quot;.</text></comment>
<story><title>Proposal to Merge Pyston with Cpython</title><url>https://discuss.python.org/t/contributing-the-pyston-jit/24195</url></story><parent_chain><item><author>martopix</author><text>Can anyone that understands these things (i.e. not me, a meek python end user) explain this in simpler terms?&lt;p&gt;I checked th Pyston website, it essentially says it makes your code faster and nothing about what&amp;#x27;s the catch and how it magically works.</text></item></parent_chain><comment><author>nine_k</author><text>Pyston is JIT compiler, which translates frequently executed bytecode into native code. JIT compilers are what makes Java and JavaScript fast. Pyston&amp;#x27;s case is closer to JavaScript, I suppose.&lt;p&gt;Since profiling and translation take time, it benefits mostly long-running code, especially servers, and is less useful for transient utilities.</text></comment>