4 ms·

Try to rewrite something simple written in Python in C++ first and measure the differences in speed/dev time first. Chances are you may end up with a story lik

by ii 18y ago

Try to rewrite something simple written in Python in C++ first and measure the differences in speed/dev time first. Chances are you may end up with a story like this: http://groups.google.com/group/comp.lang.python/browse_thread/thread/a63979a6f18bf37/b926deb737ab71c6 http://groups.google.com/group/comp.lang.python/browse_threa... Albeit micro-benchmarks may indicate that Python is 100-200 times slower than C++, they may not be applicable to the real world. Python can be very efficient. And when combined with libraries like NumPy, beating it's performance with hand-crafted C++ is difficult. Emperor has no clothes.

hugh 18y ago
Interestingly, I tried rewriting one of my C++ codes in Python one day, using numpy. It was mostly manipulation of largish (~1000 x 1000) matrices. On the upside, it was 100 lines instead of several thousand. On the downside, it was several hundred times slower. I didn't bother trying to write serious simulation codes in Python after that.
- riobard 18y ago
  every tried NumPy? guess that's what you need for the matrices stuff ...
- ii 18y ago
  Of course C++ will beat Python in speed if you invest enough time in it. And assembly will beat C/C++ if you invest even more time. My point is that some people assume that if they would just sit and write something in C++ without putting enough time and effort and skill in it, it would be somehow magically faster and better than high-level language, just because it's C++. They are mistaken. Python standard library is extremely fast. For example 'list.sort()' in Pytohn could run 3 times faster than C++ 'sort(vector<string>)'. Here are few examples when simple Python code runs faster than the same code in C++: http://groups.google.com/group/comp.lang.python/browse_thread/thread/70f9bd389473207b/74807f553ae12b8c http://groups.google.com/group/comp.lang.python/browse_threa...
  - salaam 18y ago
    "For example 'list.sort()' in Pytohn could run 3 times faster than C++ 'sort(vector<string>)'" Again comparing apples to oranges.
quasimojo 18y ago
indeed. and lets remember that all of the built-ins in perl, php, python etc are written in c and compiled and optimized and debugged.
- alecco 18y ago
  Python's pypy is written in RPython (it is python but with less features.) And it is already getting close to the main interpreter in C. I can't wait for them to finally get the on the fly compiler working. Good times coming in the language competition.

by ii 18y ago

hugh 18y ago

Interestingly, I tried rewriting one of my C++ codes in Python one day, using numpy. It was mostly manipulation of largish (~1000 x 1000) matrices. On the upside, it was 100 lines instead of several thousand. On the downside, it was several hundred times slower. I didn't bother trying to write serious simulation codes in Python after that.

riobard 18y ago
every tried NumPy? guess that's what you need for the matrices stuff ...
ii 18y ago
Of course C++ will beat Python in speed if you invest enough time in it. And assembly will beat C/C++ if you invest even more time. My point is that some people assume that if they would just sit and write something in C++ without putting enough time and effort and skill in it, it would be somehow magically faster and better than high-level language, just because it's C++. They are mistaken. Python standard library is extremely fast. For example 'list.sort()' in Pytohn could run 3 times faster than C++ 'sort(vector<string>)'. Here are few examples when simple Python code runs faster than the same code in C++: http://groups.google.com/group/comp.lang.python/browse_thread/thread/70f9bd389473207b/74807f553ae12b8c http://groups.google.com/group/comp.lang.python/browse_threa...
- salaam 18y ago
  "For example 'list.sort()' in Pytohn could run 3 times faster than C++ 'sort(vector<string>)'" Again comparing apples to oranges.

quasimojo 18y ago

indeed. and lets remember that all of the built-ins in perl, php, python etc are written in c and compiled and optimized and debugged.

alecco 18y ago
Python's pypy is written in RPython (it is python but with less features.) And it is already getting close to the main interpreter in C. I can't wait for them to finally get the on the fly compiler working. Good times coming in the language competition.