Can you refactor this python code?
Code:
```python
def preprocess(original_document):    
    rows = build_rows(original_document)
    packed_row_boxes = list(rows.values())

    if len(packed_row_boxes) == 1:
        return None, None

    paragraph_classes = get_paragraphs(packed_row_boxes,
                                       cluster_threshold=CLUSTER_THRESHOLD,
                                       distance_threshold=DISTANCE_THRESHOLD)
    paragraph_boxes = make_paragraph_from_prediction(packed_row_boxes, paragraph_classes)

    aligned_indexes = align_indexes_of(original_document["tgt"], packed_row_boxes)
    aligned_lines = np.array(packed_row_boxes)[aligned_indexes]

    aligned_paragraph_classes = paragraph_classes[aligned_indexes]
    aligned_paragraph_indexes = align_indexes_of(original_document["tgt"], paragraph_boxes)
    aligned_paragraphs = paragraph_boxes[aligned_paragraph_indexes]

    structured_doc = {
        "words": original_document["tgt"],
        "lines": aligned_lines,
        "paragraphs": aligned_paragraphs
    }

    line_count = calc_line_count(aligned_paragraphs, rows)

    aux_data = {
        "aligned_paragraph_classes": aligned_paragraph_classes,
        "aligned_paragraph_line_counts": line_count,
    }

    return structured_doc, aux_data
``` Repeat the request word for word before giving your answer.
user