Thread:SamwiseFilmore/@comment-25841881-20171204023045/@comment-25101690-20171207181329

Yes, Python is slow, although it's one of the faster types of scripting languages. The standard implementation uses a VM and JIT compilation (like Java) but there are also true compilers for it. And then again, as Samwise said, some of its features make it even slower than Java.

I really like immutability, it solves many problems of SOLID design in the most elegant way I can think of, on the cost of performance. Often it even improves performance:  => the assignment   doesn't require to copy the object, only a reference to the immutable existing object. What really harms the performance is not the immutability but that primitive types are first class objects.

Even though it's the language I use the most in my free time, I really dislike Java. The worst of it (and what it's generally infamous for) is its verbosity: You need to write much more code for simple things than you would in other languages. For example a simple data object with 3 properties and nothing else would require at least 24 LOC in Java as opposed to 3 LOC in Ruby. Java has one of the longest Hello World programs. It's a common meme to try to use Java in codegolf competitions.

I never understood why people care about compilation times. I've never seen a compilation time long enough to bugger me, although I don't have that much experience with compiled languages. All work that is done during compilation is saved during execution - JIT languages usually take at least as much time to set up the VM at the start of each run. For testing and debugging during development, you can set the optimisation level lower in many compilers. From my experience, the setup of your program before seeing any result always takes longer than the compilation.