FastAPI service wrapping the Surya-OCR-2 model (datalab-to) served through vLLM: legacy /v1/api/ai/* endpoints, an OpenAI-compatible /v1/chat/completions endpoint, a coalescing request batcher, a local OCR CLI, Docker packaging, multilingual example outputs, and quantization/concurrency benchmarks. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
243 lines
6.6 KiB
Python
243 lines
6.6 KiB
Python
import io
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import tempfile
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from typing import List
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import pypdfium2
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from surya.debug.draw import draw_polys_on_image, draw_bboxes_on_image
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from PIL import Image
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from surya.settings import settings
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from vllm_tools import predictors_vllm, ocr_vllm
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predictors = predictors_vllm
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def rescale_bbox(bbox, source_size, target_size):
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width_ratio = target_size[0] / source_size[0]
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height_ratio = target_size[1] / source_size[1]
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return [
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bbox[0] * width_ratio,
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bbox[1] * height_ratio,
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bbox[2] * width_ratio,
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bbox[3] * height_ratio,
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]
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def expand_bbox(bbox, margin=5):
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return [
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max(0, int(bbox[0]) - margin),
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max(0, int(bbox[1]) - margin),
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int(bbox[2]) + margin,
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int(bbox[3]) + margin,
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]
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def page_counter(pdf_file):
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doc = open_pdf(pdf_file)
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doc_len = len(doc)
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doc.close()
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return doc_len
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def ocr_errors(pdf_file, page_count, sample_len=512, max_samples=10, max_pages=15):
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from pdftext.extraction import plain_text_output
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with tempfile.NamedTemporaryFile(suffix=".pdf") as f:
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f.write(pdf_file.getvalue())
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f.seek(0)
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# Sample the text from the middle of the PDF
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page_middle = page_count // 2
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page_range = range(
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max(page_middle - max_pages, 0), min(page_middle + max_pages, page_count)
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)
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text = plain_text_output(f.name, page_range=page_range)
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sample_gap = len(text) // max_samples
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if len(text) == 0 or sample_gap == 0:
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return "This PDF has no text or very little text", ["no text"]
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if sample_gap < sample_len:
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sample_gap = sample_len
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# Split the text into samples for the model
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samples = []
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for i in range(0, len(text), sample_gap):
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samples.append(text[i : i + sample_len])
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results = predictors["ocr_error"](samples)
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label = "This PDF has good text."
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if results.labels.count("bad") / len(results.labels) > 0.2:
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label = "This PDF may have garbled or bad OCR text."
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return label, results.labels
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def text_detection(img):
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text_pred = predictors["detection"]([img])[0]
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text_polygons = [p.polygon for p in text_pred.bboxes]
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det_img = draw_polys_on_image(text_polygons, img.copy())
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return det_img, text_pred
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def layout_detection(img):
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pred = predictors["layout"]([img])[0]
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polygons = [p.polygon for p in pred.bboxes]
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labels = [
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f"{p.label}-{p.position}-{round(p.top_k[p.label], 2)}" for p in pred.bboxes
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]
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layout_img = draw_polys_on_image(
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polygons, img.copy(), labels=labels, label_font_size=18
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)
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return layout_img, pred
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def table_recognition(
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img, highres_img, skip_table_detection: bool
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):
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if skip_table_detection:
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layout_tables = [(0, 0, highres_img.size[0], highres_img.size[1])]
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table_imgs = [highres_img]
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else:
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_, layout_pred = layout_detection(img)
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layout_tables_lowres = [
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line.bbox
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for line in layout_pred.bboxes
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if line.label in ["Table", "TableOfContents"]
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]
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table_imgs = []
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layout_tables = []
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for tb in layout_tables_lowres:
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highres_bbox = rescale_bbox(tb, img.size, highres_img.size)
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# Slightly expand the box
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highres_bbox = expand_bbox(highres_bbox)
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table_imgs.append(highres_img.crop(highres_bbox))
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layout_tables.append(highres_bbox)
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table_preds = predictors["table_rec"](table_imgs)
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table_img = img.copy()
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for results, table_bbox in zip(table_preds, layout_tables):
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adjusted_bboxes = []
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labels = []
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colors = []
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for item in results.cells:
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adjusted_bboxes.append(
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[
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(item.bbox[0] + table_bbox[0]),
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(item.bbox[1] + table_bbox[1]),
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(item.bbox[2] + table_bbox[0]),
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(item.bbox[3] + table_bbox[1]),
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]
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)
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labels.append(item.label)
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if "Row" in item.label:
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colors.append("blue")
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else:
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colors.append("red")
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table_img = draw_bboxes_on_image(
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adjusted_bboxes,
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highres_img,
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labels=labels,
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label_font_size=18,
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color=colors,
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)
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return table_img, table_preds
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# Function for OCR
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def ocr(
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img: Image.Image,
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highres_img: Image.Image,
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skip_text_detection: bool = False,
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recognize_math: bool = True,
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with_bboxes: bool = True,
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):
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return ocr_vllm(
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img,
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highres_img,
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skip_text_detection=skip_text_detection,
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recognize_math=recognize_math,
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with_bboxes=with_bboxes,
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)
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def open_pdf(pdf_file):
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stream = io.BytesIO(pdf_file.getvalue())
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return pypdfium2.PdfDocument(stream)
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def get_page_image(pdf_file, page_num, dpi=settings.IMAGE_DPI):
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doc = open_pdf(pdf_file)
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renderer = doc.render(
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pypdfium2.PdfBitmap.to_pil,
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page_indices=[page_num - 1],
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scale=dpi / 72,
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)
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png = list(renderer)[0]
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png_image = png.convert("RGB")
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doc.close()
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return png_image
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def page_counter(pdf_file):
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doc = open_pdf(pdf_file)
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doc_len = len(doc)
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doc.close()
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return doc_len
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import pandas as pd
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def bbox_intersection(box1, box2):
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x1 = max(box1[0], box2[0])
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y1 = max(box1[1], box2[1])
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x2 = min(box1[2], box2[2])
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y2 = min(box1[3], box2[3])
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if x1 < x2 and y1 < y2:
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return (x1, y1, x2, y2)
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else:
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return None
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def area_of_bbox(box):
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return (box[2] - box[0]) * (box[3] - box[1])
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def is_bbox_inside(box, parent_box):
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interaction_box = bbox_intersection(box, parent_box)
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if interaction_box is None:
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return False
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return area_of_bbox(interaction_box) / area_of_bbox(box) > 0.5
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def center_of_bbox(box):
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return ((box[0] + box[2]) / 2, (box[1] + box[3]) / 2)
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def extract_text_from_image(image):
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layout_predictor = predictors["layout"]
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recognition_predictor = predictors["recognition"]
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layout_prediction = layout_predictor([image])[0]
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prediction = recognition_predictor([image], [layout_prediction], full_page=False)[0]
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items = [
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{
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"text": block.html,
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"position": block.reading_order,
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"order_value": block.bbox[1],
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}
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for block in prediction.blocks
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if not block.skipped and not block.error and block.html
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]
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if not items:
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return ""
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df = pd.DataFrame(items)
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df = df.sort_values(by=['position', 'order_value'])
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ds = df.groupby('position').apply(lambda x: " ".join(x['text'].tolist()))
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full_text = "\n\n".join(ds.to_list())
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return full_text
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