Lazily import the numpy module

def numpy():
        '''Lazily import the numpy module'''
        if LazyImport.numpy_module is None:
            try:
                LazyImport.numpy_module = __import__('numpypy')
            except ImportError:
                try:
                    LazyImport.numpy_module = __import__('numpy')
                except ImportError:
                    raise ImportError('The numpy module is required')
        return LazyImport.numpy_module