On Thursday, April 30, 2015 at 6:10:58 PM UTC-4, Scott Jones wrote: > > Yes... Python will win on string processing... esp. with Python 3... I > quickly ran into things that were > 800x faster in Python... > (I hope to help change that though!) >
The "800x" faster example that you've referred to several times, if I recall correctly, is one where you repeatedly concatenate strings. In CPython, under certain circumstances, this is optimized to mutating one of the strings in-place and is consequently O(n) where n is the final length, although this is not guaranteed by the language itself. In Julia, Ruby, Java, Go, and many other languages, concatenation allocates a new string and hence building a string by repeated concatenation is O(n^2). That doesn't mean that those other languages "lose" on string processing to Python, it just means that you have to do things slightly differently (e.g. write to an IOBuffer in Julia). You can't always expect the *same code* (translated as literally as possible) to be the optimal approach in different languages, and it is inflammatory to compare languages according to this standard. A fairer question is whether it is *much harder* to get good performance in one language vs. another for a certain task. There will certainly be tasks where Python is still superior in this sense simply because there are many cases where Python calls highly tuned C libraries for operations that have not been as optimized in Julia. Julia will tend to shine the further you stray from "built-in" operations in your performance-critical code.
