Get root directory and full name of module from .py file for import

I am looking for an easy and quick way to find the package root and fully qualified module name from a .py file path.

I want the user to select the .py and import it without breaking. Import a module if part of the package is likely to break. Thus, I want to automatically add the directory where the package root is in sys.path (if it doesn't already exist) and then import the module with the fully qualified module name.

I am not running anywhere from the same directory or from this script, so I cannot use __file__

something like that either. Also, I haven't imported the module yet, so I can't (as far as I know) check the module object because it doesn't exist.

This is a working version, but I am interested in finding easier / faster solutions.

def splitPathFull(path):
    folders=[]
    while 1:
        path,folder=os.path.split(path)

        if folder!="":
            folders.append(folder)
        else:
            if path!="":
                folders.append(path)

            break

    folders.reverse()
    return folders

def getPackageRootAndModuleNameFromFilePath(filePath):
    """
        It recursively looks up until it finds a folder without __init__.py and uses that as the root of the package
        the root of the package.
    """
    folder = os.path.dirname(filePath)
    if not os.path.exists( folder ):
        raise RuntimeError( "Location does not exist: {0}".format(folder) )

    if not filePath.endswith(".py"):
        return None

    moduleName = os.path.splitext( os.path.basename(filePath) )[0] # filename without extension

    #
    # If there a __init__.py in the folder:
    #   Find the root module folder by recursively going up until there no more __init__.py
    # Else:
    #   It a standalone module/python script.
    #
    foundScriptRoot = False
    fullModuleName = None
    rootPackagePath = None
    if not os.path.exists( os.path.join(folder, "__init__.py" ) ):
        rootPackagePath = folder
        fullModuleName = moduleName
        foundScriptRoot = True
        # It not in a Python package but a seperate ".py" script
        # Thus append it directory name to sys path (if not in there) and import the .py as a module
    else:
        startFolder = folder

        moduleList = []
        if moduleName != "__init__":
            moduleList.append(moduleName)

        amountUp = 0
        while os.path.exists( folder ) and foundScriptRoot == False:

            moduleList.append ( os.path.basename(folder) )
            folder = os.path.dirname(folder)
            amountUp += 1

            if not os.path.exists( os.path.join(folder, "__init__.py" ) ):
                foundScriptRoot = True
                splitPath = splitPathFull(startFolder)
                rootPackagePath = os.path.join( *splitPath[:-amountUp] )
                moduleList.reverse()
                fullModuleName = ".".join(moduleList)

    if fullModuleName == None or rootPackagePath == None or foundScriptRoot == False:
        raise RuntimeError( "Couldn't resolve python package root python path and full module name for: {0}".format(filePath) )

    return [rootPackagePath, fullModuleName]

def importModuleFromFilepath(filePath, reloadModule=True):
    """
        Imports a module by it filePath.
        It adds the root folder to sys.path if it not already in there.
        Then it imports the module with the full package/module name and returns the imported module as object.
    """

    rootPythonPath, fullModuleName = getPackageRootAndModuleNameFromFilePath(filePath)

    # Append rootPythonPath to sys.path if not in sys.path
    if rootPythonPath not in sys.path:
        sys.path.append(rootPythonPath)

    # Import full (module.module.package) name
    mod = __import__( fullModuleName, {}, {}, [fullModuleName] )
    if reloadModule:
        reload(mod)

    return mod