Programmatically import Python files as modules within another Python file and run them

Question

There's a highly upvoted StackOverflow thread which says that the best way to run Python files within another Python file is to import them as a module.

That works well for me, except that I'm having trouble doing it programmatically in a case where there are at least hundreds (if not thousands) of files to be run.

All of the files are in the same directory and share a common naming convention. I tried to run them like this:

import glob, os

for filename in glob.glob("*_decomp*"):
    import filename

but that throws an error:

Traceback (most recent call last):
  File "C:\Python35\lib\site-packages\IPython\core\interactiveshell.py", line
3066, in run_code exec(code_obj, self.user_global_ns, self.user_ns) File "", line 4, in import filename File "C:\Program Files\JetBrains\PyCharm Community Edition 2017.1.3\helpers\pydev_pydev_bundle\pydev_import_hook.py", line 21, in do_import module = self._system_import(name, *args, **kwargs) ImportError: No module named 'filename'

The variable filename is also underlined in red in the IDE, which negates my original hypothesis that it was simply a matter of needing to remove the .py file extension.

This works fine for printing:

import glob, os

for filename in glob.glob("*_decomp*"):
    # import filename
    print(filename)

So I'm not really sure what the problem with the earlier statement is or how to work around it. I can also do the import manually and that works fine, but again I'd like to do it programmatically so that I don't have to type all of the file names and because the file names will change over time.

Finally, I also tried it with [:-3] (i.e. filename[:-3]) to remove the file extension, but again that only works for print() and not import.

DisappointedByUnaccountableMod · Accepted Answer · 2017-06-12T16:29:01.223

There are other ways of importing not covered by the SO link you give, for example (although I'm not holding this up as a canonical or even necessarily good way of importing, but it works for me) based on one of the examples I found via this SO question/answers Building a minimal plugin architecture in Python I wrote a simple plugin implementation below - it searches a folder called 'plugins' below wherever the .py file with this in it is. Each plugin has to implement a class called Plugin, they all get the same parameters.

path = 'plugins'
# find subdirs of the path - these are the groups
# for each group, load all the .py files, each provides one or more actions
searchdir = os.path.join(os.path.split(__file__)[0],path)
if os.access(searchdir, os.F_OK):
    print "searchdir=",searchdir
    print "results=",os.walk(searchdir)
    (root, dirs, files) =os.walk(searchdir).next()
    print root,dirs,files
    for dir in dirs:
        print "scanning dir",dir
        self.groups[dir] = []
        sys.path.insert(0, os.path.join(root,dir))
        for f in sorted(os.listdir(os.path.join(root,dir))):
            print "looking at",f
            fname, ext = os.path.splitext(f)
            if ext == '.py':
                print "importing ",f
                mod = __import__(fname)
                try:
                    self.groups[dir].append(mod.PlugIn(group,cmdobj,config, jts_data, directives, current_config_props,allcomponents,globals))
                except:
                    print "URGH! plugin instantiation error!"
                    raise
        sys.path.pop(0)
else:
    print "############# no plugins folder",searchdir

Programmatically import Python files as modules within another Python file and run them

1 Answers1