4 ms·

More portable means "can be ported to new platforms more easily", not "has been ported to new platforms by someone else". A C program (in general) is more por

More portable means "can be ported to new platforms more easily", not "has been ported to new platforms by someone else". A C program (in general) is more portable than anything written on top of C because to port, say, Python to a new platform, one has to have C there first. It has nothing to do with whether the work has been done by you or someone else. Of course, one can write code in either language which is not portable, but that is also beside the point.

lmm 11y ago
> A C program (in general) is more portable than anything written on top of C because to port, say, Python to a new platform, one has to have C there first. Port C compiler -> port your C program vs port C compiler -> port Python interpreter -> port your Python program. The latter can still end up a lot easier and cheaper, because the Python interpreter is already multi-platform and Python programs tend not to have much if any platform-specific code by the nature of the language. > It has nothing to do with whether the work has been done by you or someone else. It has everything to do with that. Ultimately via Turing equivalence it's possible to port anything to anywhere, so when we're talking about "portability" we must be talking about how much it costs to port a program to a new or existing architecture. > Of course, one can write code in either language which is not portable, but that is also beside the point. Again, it's very much the point, because it can't possibly be a yes-or-no thing. How costly is typical/idiomatic C code to port? How costly is typical/idiomatic Python code? Those are the questions that matter when we talk about language portability.
- jjnoakes 11y ago
  By definition, the C language is more portable than the Python language, because in order to run Python on a system, C must run there first. Unless you are talking about a Python not implemented in C, or a C compiler that was created to only compile the Python interpreter (and not all of the C language), then there is no other way around this simple fact. A standard-conforming program should be part of the topic here, not "typical/idiomatic" non-objective software. Just because most people may not write portable C code doesn't make the language itself more or less portable. It just makes those particular programs less portable. Plenty of C code is highly portable. Plenty is not. Same can be said of Python. It is moot. The language is under discussion here, not any set of specific programs written in the language. Also, beside that simple logical conclusion, it is 2-3 orders of magnitude easier for me to port a C program I wrote to a new platform than it is for me to port the Python interpreter just to support my Python program on a new platform. Nevermind all of the features I would have to port (or neuter) inside Python which my program may not even use.
  - lmm 11y ago
    > By definition, the C language is more portable than the Python language, because in order to run Python on a system, C must run there first. What definition are you using, and what practical use is your definition? You seem to be defining "portable" in some absurd, irrelevant way so that your preferred language "wins", regardless of what that actually means. > A standard-conforming program should be part of the topic here, not "typical/idiomatic" non-objective software. Just because most people may not write portable C code doesn't make the language itself more or less portable. It just makes those particular programs less portable. > Plenty of C code is highly portable. Plenty is not. Same can be said of Python. It is moot. The language is under discussion here, not any set of specific programs written in the language. The standard is just some words on a page. The programs and tools are what give it meaning. If 90%+ of the things we call "C programs" don't conform to the standard, it's not reasonable to treat the standard as the definition of a "C program". And for any practical, real-world decision like "should I write my program in C or Python", the typical/idiomatic is the question that matters. > it is 2-3 orders of magnitude easier for me to port a C program I wrote to a new platform than it is for me to port the Python interpreter just to support my Python program on a new platform. Nevermind all of the features I would have to port (or neuter) inside Python which my program may not even use. How often do you port things to a platform on which the Python interpreter doesn't already build? And how large are these programs for the 2-3 orders of magnitude? (I guess small in any case if you're talking about writing a program yourself rather than in a team). The Python interpreter is actually pretty small.
    - jjnoakes 11y ago
      Are you being obtuse on purpose? There are C compilers for N platforms. There are Python interpreters for M platforms. Since the Python interpreter is written in C, N >= M. The programs I have ported are more than a million lines. Not the largest, sure, but not trivial. And they run on platforms where Python does not. The size of the C code or the Python interpreter code does not matter. What does matter is what subsystems are required. Python is general purpose and has a wide set of requirements (networking, file systems, process manipulation, dynamic loading, the list is quite long). Oh, and the Python list includes compiling C programs (for extensions). A second reason backing my absurd definition. The C programming language requirements placed on the hosting environment are much smaller. So the language is more portable for that reason as well. It is beneficial to only port what you use, instead of having to port a monolithic interpreter, including the parts you don't need (which may not even run on the target platform easily or at all).

lmm 11y ago

> A C program (in general) is more portable than anything written on top of C because to port, say, Python to a new platform, one has to have C there first. Port C compiler -> port your C program vs port C compiler -> port Python interpreter -> port your Python program. The latter can still end up a lot easier and cheaper, because the Python interpreter is already multi-platform and Python programs tend not to have much if any platform-specific code by the nature of the language. > It has nothing to do with whether the work has been done by you or someone else. It has everything to do with that. Ultimately via Turing equivalence it's possible to port anything to anywhere, so when we're talking about "portability" we must be talking about how much it costs to port a program to a new or existing architecture. > Of course, one can write code in either language which is not portable, but that is also beside the point. Again, it's very much the point, because it can't possibly be a yes-or-no thing. How costly is typical/idiomatic C code to port? How costly is typical/idiomatic Python code? Those are the questions that matter when we talk about language portability.

jjnoakes 11y ago
By definition, the C language is more portable than the Python language, because in order to run Python on a system, C must run there first. Unless you are talking about a Python not implemented in C, or a C compiler that was created to only compile the Python interpreter (and not all of the C language), then there is no other way around this simple fact. A standard-conforming program should be part of the topic here, not "typical/idiomatic" non-objective software. Just because most people may not write portable C code doesn't make the language itself more or less portable. It just makes those particular programs less portable. Plenty of C code is highly portable. Plenty is not. Same can be said of Python. It is moot. The language is under discussion here, not any set of specific programs written in the language. Also, beside that simple logical conclusion, it is 2-3 orders of magnitude easier for me to port a C program I wrote to a new platform than it is for me to port the Python interpreter just to support my Python program on a new platform. Nevermind all of the features I would have to port (or neuter) inside Python which my program may not even use.
- lmm 11y ago
  > By definition, the C language is more portable than the Python language, because in order to run Python on a system, C must run there first. What definition are you using, and what practical use is your definition? You seem to be defining "portable" in some absurd, irrelevant way so that your preferred language "wins", regardless of what that actually means. > A standard-conforming program should be part of the topic here, not "typical/idiomatic" non-objective software. Just because most people may not write portable C code doesn't make the language itself more or less portable. It just makes those particular programs less portable. > Plenty of C code is highly portable. Plenty is not. Same can be said of Python. It is moot. The language is under discussion here, not any set of specific programs written in the language. The standard is just some words on a page. The programs and tools are what give it meaning. If 90%+ of the things we call "C programs" don't conform to the standard, it's not reasonable to treat the standard as the definition of a "C program". And for any practical, real-world decision like "should I write my program in C or Python", the typical/idiomatic is the question that matters. > it is 2-3 orders of magnitude easier for me to port a C program I wrote to a new platform than it is for me to port the Python interpreter just to support my Python program on a new platform. Nevermind all of the features I would have to port (or neuter) inside Python which my program may not even use. How often do you port things to a platform on which the Python interpreter doesn't already build? And how large are these programs for the 2-3 orders of magnitude? (I guess small in any case if you're talking about writing a program yourself rather than in a team). The Python interpreter is actually pretty small.
  - jjnoakes 11y ago
    Are you being obtuse on purpose? There are C compilers for N platforms. There are Python interpreters for M platforms. Since the Python interpreter is written in C, N >= M. The programs I have ported are more than a million lines. Not the largest, sure, but not trivial. And they run on platforms where Python does not. The size of the C code or the Python interpreter code does not matter. What does matter is what subsystems are required. Python is general purpose and has a wide set of requirements (networking, file systems, process manipulation, dynamic loading, the list is quite long). Oh, and the Python list includes compiling C programs (for extensions). A second reason backing my absurd definition. The C programming language requirements placed on the hosting environment are much smaller. So the language is more portable for that reason as well. It is beneficial to only port what you use, instead of having to port a monolithic interpreter, including the parts you don't need (which may not even run on the target platform easily or at all).