Finding the name of your caller in Python

April 20, 2008

One of the things that would be useful in an access tracer is reporting not just what was accessed, but where it was accessed from. A basic starter for this is knowing what function called you.

CPython has enough introspection faculties to give you this information, but it's not entirely documented how to dig it out. The big tool for this is the inspect module, and we can use it to define a function:

import inspect
def getcallerinfo():
    fr = inspect.currentframe()
        fr = fr.f_back.f_back
        if fr is None:
            return "<no caller>"
        fi = inspect.getframeinfo(fr, 0)
        if fi[2] == "<module>":
            return "(%s:%d)" % (fi[0], fi[1])
            return "%s() (%s:%d)" % (fi[2],
                                     fi[0], fi[1])
        del fr

This returns something like 'barfunc() (', which means that the function that called getcallerinfo() was called by barfunc(), specifically the code at line 30 of

Technically we don't need to call inspect.getframeinfo() to obtain this information (we could just use fr.f_code.co_filename and so on directly, since they're documented), but it handles some peculiar magic with the file name for us.

(Needless to say, this is probably specific to CPython; I would be surprised if the same code worked in Jython or IronPython or the like. Since all of this is documented, it is at least likely to be portable across different versions of CPython and to keep working in future ones.)

Written on 20 April 2008.
« What FAQs are
Dear ZFS: please stop having your commands stall »

Page tools: View Source, Add Comment.
Login: Password:
Atom Syndication: Recent Comments.

Last modified: Sun Apr 20 23:04:48 2008
This dinky wiki is brought to you by the Insane Hackers Guild, Python sub-branch.