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Wow, I don't think I've ever had such a visceral reaction to anything I've posted on HN before. By people who clearly didn't take the time out of their day to e

by azylman 14y ago

Wow, I don't think I've ever had such a visceral reaction to anything I've posted on HN before. By people who clearly didn't take the time out of their day to even read what I posted! Basically, I don't use python very much and wanted to know if python had performance issues that required you to drop down to C code often, or if that was just for a scenario such as this. I think that any language that REQUIRES you to drop down to a lower level for performance (not one that SUPPORTS it, but one where it's REQUIRED) is inherently broken. I would think that would be a pretty noncontroversial statement - if every python script you wrote had to have embedded C code because otherwise it was too slow, that would be pretty broken. That's why I wanted to know how common this was.

bryanh 14y ago
I think the reaction was because you put Python in a broadly negative camp by infering ctype extensions are required for any sort of performant code. Its actually relatively uncommon to use ctypes and most developers who use Python know this. Python is a great general purpose language and is used as such. No one would be silly enough to solely rely on it in highly performance sensitive environments (IE: 3d renderers or high frequency trading). Just like no one would be silly enough to write an entire CRUD web app in C. The point is, Python isn't broken and claiming that it may be because you read a short article on a Python feature got you the negative reaction.
- azylman 14y ago
  I never inferred that ctypes were required - in fact, I explicitly did the opposite. I asked if it was required for performant code. See the part of my post where I said "To regular pythonistas: Is this a common issue with Python, or only in the author's contrived scenario of summing a ridiculous amount of numbers?" I also never claimed that python was broken.
  - bryanh 14y ago
    > I'm not a big user of Python, but it seems to me that any language that requires you to embed a different language for performance is inherently broken. It seems like you imply both of those things, though perhaps not as explicit as "Python is broken because ctypes are required", which you did not say.
dbecker 14y ago
Whether calling c is "required" depends on a few things. The relative importance of run-time vs programming-time, the nature of the problem, etc. I've been doing scientific programming in Python for 4 years, and I've never felt I needed to drop to C (though I was aware of the option.) The hard computing for most problems is done in calls to a few libraries that wrap highly optimized code from lower level languages. So matrix inversion, arithmetic on arrays, etc are just as fast in python as in C or Fortran. If your work can't be done using library calls, pure python is going to be much slower.
dagw 14y ago
Words like "Slow" and "Performance" are very relative. Yes python (well at least cPython) is a very slow language (on par with the likes of ruby, lua, perl, php etc.) and yes if you really need performance you really need C (again, not that different from the above mentioned language) and yes most non-trivial python code relies on C/C++ in at least some point. However very few python coders find themselves actually writing C code when working in Python. Most rely on existing libraries that put a nice python wrapper around highly tuned C code, and in many cases most python programmers are only vaguely aware of which libraries are pure python and which are wrappers. I think that any language that REQUIRES you to drop down to a lower level for performance. Again without defining "performance" this statement means nothing. All languages (even C) have cases where you are required to drop down to a lower level to get the fastest possible performance. That's why I wanted to know how common this was. Depends very much on what you're doing. If you're doing web development, it's very uncommon. If you're doing fairly performance critical numerical work over very large data sets, then it's much more common (but even in that case the kind folks over at numpy and friends have done 98% of the hard work for you).

by azylman 14y ago

bryanh 14y ago

I think the reaction was because you put Python in a broadly negative camp by infering ctype extensions are required for any sort of performant code. Its actually relatively uncommon to use ctypes and most developers who use Python know this. Python is a great general purpose language and is used as such. No one would be silly enough to solely rely on it in highly performance sensitive environments (IE: 3d renderers or high frequency trading). Just like no one would be silly enough to write an entire CRUD web app in C. The point is, Python isn't broken and claiming that it may be because you read a short article on a Python feature got you the negative reaction.

azylman 14y ago
I never inferred that ctypes were required - in fact, I explicitly did the opposite. I asked if it was required for performant code. See the part of my post where I said "To regular pythonistas: Is this a common issue with Python, or only in the author's contrived scenario of summing a ridiculous amount of numbers?" I also never claimed that python was broken.
- bryanh 14y ago
  > I'm not a big user of Python, but it seems to me that any language that requires you to embed a different language for performance is inherently broken. It seems like you imply both of those things, though perhaps not as explicit as "Python is broken because ctypes are required", which you did not say.

dbecker 14y ago

Whether calling c is "required" depends on a few things. The relative importance of run-time vs programming-time, the nature of the problem, etc. I've been doing scientific programming in Python for 4 years, and I've never felt I needed to drop to C (though I was aware of the option.) The hard computing for most problems is done in calls to a few libraries that wrap highly optimized code from lower level languages. So matrix inversion, arithmetic on arrays, etc are just as fast in python as in C or Fortran. If your work can't be done using library calls, pure python is going to be much slower.

dagw 14y ago

Words like "Slow" and "Performance" are very relative. Yes python (well at least cPython) is a very slow language (on par with the likes of ruby, lua, perl, php etc.) and yes if you really need performance you really need C (again, not that different from the above mentioned language) and yes most non-trivial python code relies on C/C++ in at least some point. However very few python coders find themselves actually writing C code when working in Python. Most rely on existing libraries that put a nice python wrapper around highly tuned C code, and in many cases most python programmers are only vaguely aware of which libraries are pure python and which are wrappers. I think that any language that REQUIRES you to drop down to a lower level for performance. Again without defining "performance" this statement means nothing. All languages (even C) have cases where you are required to drop down to a lower level to get the fastest possible performance. That's why I wanted to know how common this was. Depends very much on what you're doing. If you're doing web development, it's very uncommon. If you're doing fairly performance critical numerical work over very large data sets, then it's much more common (but even in that case the kind folks over at numpy and friends have done 98% of the hard work for you).