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Question

I have a function which is stored in builtins. This is used to load python modules with relative paths from the projects base directory. The projecs base directory is stored under builtins.absolute

Function below:

def projectRelativeImport(fileName, projectRelativePath, moduleName = None):
    # if moduleName not set, set it to file name with first letter capatilised
    if moduleName is None:
        moduleName = fileName[:1].capitalize() + fileName[1:]

    # we shouldn't be passing fileName with an extension unless moduleName is set due to previous if. So in those cases we add .py
    if len(fileName) >= 3 and fileName[-3:] != '.py':
        fileName = fileName + '.py'

    dir = os.path.join(builtins.absolute, projectRelativePath)
    full = os.path.join(dir, fileName)

    sys.path.append(dir)
    imp.load_source(moduleName, full)
    sys.path.remove(dir)

On one of my other files I use projectRelativeImport('inputSaveHandler', 'app/util', 'SaveHandler') to import SaveHandler from app/util/inputSaveHandler.py. This runs through the project RelativeImport absolutely fine. Correct strings are being used by imp, I've printed to check.

But a couple of lines after that execution I have a line

handler = SaveHandler.ConfHandler()

Which throws NameError: name 'SaveHandler' is not defined

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I realise my project relative import function is a bit odd, especially since I have it globally saved using builtins (there's probably a better way but I only started using python over the last two days). But I'm just a bit confused as to why the name isn't being recognised. Do I need to return something from imp due to scope being rubbish as the project relative import function is in a different file?

Answer 1

I fixed this by returning from projectRelativeImport() what was passed back from imp.load_source as shown below:

sys.path.append(dir)
submodule = imp.load_source(moduleName, full)
sys.path.remove(dir)
return submodule

Then when I used the import function the returned value now goes to a variable with the same name as that I gave to the module (all very strange)

SaveHandler = projectRelativeImport('inputSaveHandler', 'app/util', 'SaveHandler')

I got to this because it worked no problem from the file projectRelativeImport was defined in but not in any others. So it was clearly a scope issue to me, so I figured I'd just try returning whatever imp gave me and it worked