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jeanbigboute at gmail.com wrote: > I am trying to write some recursive code to explore the methods, classes, > functions, builtins, etc. of a package all the way down the hierarchy. > > 1) Preliminaries > In [2]: def explore_pkg(pkg): > ...: return dir(pkg) > ...: > > In [3]: import numpy as np > > In [4]: l2 = explore_pkg(np.random) > > In [5]: len(l2) > Out[5]: 72 # np.random has 72 'things' underneath it > > In [6]: l2[0:5] > Out[6]: ['Lock', 'RandomState', '__RandomState_ctor', '__all__', > '__builtins__'] > > 2) I ultimately need to create inputs to explore_pkg programmatically en > route to a recursively called function. The only way I can think of is to > use strings. But, passing a string such as 'np.random' into explore_pkg > correctly returns the methods/... associated with the string and not the > module np.random > > e.g. explore_pkg('np.random') will NOT do what I want > > explore_pkg(eval('np.random')) does work but I understand eval is > dangerous and not to be trifled with. There's no point preventing a person from doing eval("shutil.rmtree('/')'") that can type >>> import shutil >>> shutil.rmtree("/") For personal tools I have no qualms using it if it simplifies the resulting code significantly. Most of the time it doesn't... > explore_pkg(getattr(np,'random')) works but if I want to go deeper, I have > to nest getattrs. If you don't want to write out that for loop use reduce(): >>> import functools >>> class A: pass ... >>> a = A() >>> a.b = A() >>> a.b.c = A() >>> a.b.c.d = 42 >>> functools.reduce(getattr, "b.c.d".split("."), a) 42 > > Question: Is there a solution to this "turn a string into the module it > represents" problem? I have a vague feeling decorators might be what I > need but they've always confused me. > > I have searched extensively but couldn't find anything directly related to > this. If you use the original module name rather than the np alias it's easy: >>> import importlib >>> importlib.import_module("numpy.random") <module 'numpy.random' from '/usr/lib/python3/dist- packages/numpy/random/__init__.py'> If you want to check the __main__ module first: >>> import numpy as np >>> import __main__ >>> import functools >>> functools.reduce(getattr, "np.random".split("."), __main__) <module 'numpy.random' from '/usr/lib/python3/dist- packages/numpy/random/__init__.py'>

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