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For reasons I won't get into, I need some way to literally print a function.

I know when you run print on a function object you get some complicated <010101045 function> output. So to my understanding perhaps the only way to do this is run some kind of python notepad module. Then I could devise an algorithm to write a line of text to match each function line so as to get a printed function.

If anyone knows some other way to achieve this, please do tell because I am sure doing it this way is incredibly complicated. If however this is the only way, if someone could walk me through the basic steps to doing so that would also be greatly appreciated.

It occurred to me also that it would be interesting to be able to have the syntax of the printed function be saved in python format so that I could literally just import it directly into a program if I wanted. Yes, I realize this is getting really complicated, but again, a general walk through would be really cool if anyone knows how to do this.

If anyone has gotten as far as automating the aforementioned process to the point where a program could modify an imported module from inside of the program importing it, now that would really cool.

(In an ideal case of course the modified version would be saved under a different name and be imported as well as the previous version and handled at that point within the program doing the importing)

I guess at this point I'm just curious about the basic commands for importing, saving, and modifying of files from within a python program.

All insight is appreciated,

Thanks,

PS: if you are wondering why I want to do all of this, it should be obvious, if not it would take a while to explain.

CodeHard_or_HardCode
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    http://stackoverflow.com/questions/427453/how-can-i-get-the-source-code-of-a-python-function – Amadan Dec 11 '13 at 03:38

1 Answers1

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Use inspect.getsource:

def a():
    pass

import inspect
print inspect.getsource(a)

Of course, this only works if you have access to the original source.

If you don't have the original source, the most you could get is the byte code (see dis.dis).

EDIT: The Python interactive shell is one example where inspect does not have access to the source.

Paul Draper
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  • This will give you an IOError unless the function is defined in-file – samrap Dec 11 '13 at 03:40
  • Nope. It works for just fine for me, as long as the source is still available, even if it is another file. Note that the source code *does not* work in the Python interactive shell. – Paul Draper Dec 11 '13 at 03:43
  • Ahh, handy that. Any thoughts on how I might be able to write that code directly into the program while its running? – CodeHard_or_HardCode Dec 11 '13 at 03:47
  • @Nick, you mean like `eval` or `exec`? – Paul Draper Dec 11 '13 at 03:48
  • I'm not sure, maybe. What would be nice is if I could have it copied directly from inspect.getsource() so that I don't have to copy and paste it manually and the one bit of output I need doesn't get lost in a sea of print lines. – CodeHard_or_HardCode Dec 11 '13 at 03:53
  • I don't think eval or exec will work. If I were to print "var = 1", I need a command that will write that into the bottom of the program, and in this case I need what's written to be the printed function. – CodeHard_or_HardCode Dec 11 '13 at 04:07