feat: added excel backend

docling/backend/msexcel_backend.py

@@ -0,0 +1,326 @@
+import logging
+from io import BytesIO
+from pathlib import Path
+from typing import Dict, Set, Tuple, Union
+
+from docling_core.types.doc import (
+    DoclingDocument,
+    DocumentOrigin,
+    GroupLabel,
+    ImageRef,
+    TableCell,
+    TableData,
+)
+
+# from lxml import etree
+from openpyxl import Workbook, load_workbook
+from openpyxl.cell.cell import Cell
+from openpyxl.drawing.image import Image
+from openpyxl.worksheet.worksheet import Worksheet
+
+from docling.backend.abstract_backend import DeclarativeDocumentBackend
+from docling.datamodel.base_models import InputFormat
+from docling.datamodel.document import InputDocument
+
+_log = logging.getLogger(__name__)
+
+from typing import Any, List
+
+from pydantic import BaseModel
+
+
+class ExcelCell(BaseModel):
+    row: int
+    col: int
+    text: str
+    row_span: int
+    col_span: int
+
+
+class ExcelTable(BaseModel):
+    num_rows: int
+    num_cols: int
+    data: List[ExcelCell]
+
+
+class MsExcelDocumentBackend(DeclarativeDocumentBackend):
+
+    def __init__(self, in_doc: "InputDocument", path_or_stream: Union[BytesIO, Path]):
+        super().__init__(in_doc, path_or_stream)
+
+        # Initialise the parents for the hierarchy
+        self.max_levels = 10
+
+        self.parents: Dict[int, Any] = {}
+        for i in range(-1, self.max_levels):
+            self.parents[i] = None
+
+        self.workbook = None
+        try:
+            if isinstance(self.path_or_stream, BytesIO):
+                self.workbook = load_workbook(filename=self.path_or_stream)
+
+            elif isinstance(self.path_or_stream, Path):
+                self.workbook = load_workbook(filename=str(self.path_or_stream))
+
+            self.valid = True
+        except Exception as e:
+            self.valid = False
+
+            raise RuntimeError(
+                f"MsPowerpointDocumentBackend could not load document with hash {self.document_hash}"
+            ) from e
+
+    def is_valid(self) -> bool:
+        _log.info(f"valid: {self.valid}")
+        return self.valid
+
+    @classmethod
+    def supports_pagination(cls) -> bool:
+        return True
+
+    def unload(self):
+        if isinstance(self.path_or_stream, BytesIO):
+            self.path_or_stream.close()
+
+        self.path_or_stream = None
+
+    @classmethod
+    def supported_formats(cls) -> Set[InputFormat]:
+        return {InputFormat.XLSX}
+
+    def convert(self) -> DoclingDocument:
+        # Parses the XLSX into a structured document model.
+
+        origin = DocumentOrigin(
+            filename=self.file.name or "file.xlsx",
+            mimetype="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
+            binary_hash=self.document_hash,
+        )
+
+        doc = DoclingDocument(name=self.file.stem or "file.xlsx", origin=origin)
+
+        if self.is_valid():
+            doc = self._convert_workbook(doc)
+        else:
+            raise RuntimeError(
+                f"Cannot convert doc with {self.document_hash} because the backend failed to init."
+            )
+
+        return doc
+
+    def _convert_workbook(self, doc: DoclingDocument) -> DoclingDocument:
+
+        if self.workbook is not None:
+
+            # Iterate over all sheets
+            for sheet_name in self.workbook.sheetnames:
+                _log.info(f"Processing sheet: {sheet_name}")
+
+                # Access the sheet by name
+                sheet = self.workbook[sheet_name]
+
+                self.parents[0] = doc.add_group(
+                    parent=None,
+                    label=GroupLabel.SECTION,
+                    name=f"sheet: {sheet_name}",
+                )
+
+                doc = self._convert_sheet(doc, sheet)
+        else:
+            _log.error("Workbook is not initialized.")
+
+        return doc
+
+    def _convert_sheet(self, doc: DoclingDocument, sheet: Worksheet):
+
+        doc = self._find_tables_in_sheet(doc, sheet)
+
+        doc = self._find_images_in_sheet(doc, sheet)
+
+        return doc
+
+    def _find_tables_in_sheet(self, doc: DoclingDocument, sheet: Worksheet):
+
+        tables = self._find_data_tables(sheet)
+
+        for excel_table in tables:
+            num_rows = excel_table.num_rows
+            num_cols = excel_table.num_cols
+
+            table_data = TableData(
+                num_rows=num_rows,
+                num_cols=num_cols,
+                table_cells=[],
+            )
+
+            for excel_cell in excel_table.data:
+
+                cell = TableCell(
+                    text=excel_cell.text,
+                    row_span=excel_cell.row_span,
+                    col_span=excel_cell.col_span,
+                    start_row_offset_idx=excel_cell.row,
+                    end_row_offset_idx=excel_cell.row + excel_cell.row_span,
+                    start_col_offset_idx=excel_cell.col,
+                    end_col_offset_idx=excel_cell.col + excel_cell.col_span,
+                    col_header=False,
+                    row_header=False,
+                )
+                table_data.table_cells.append(cell)
+
+            doc.add_table(data=table_data, parent=self.parents[0])
+
+        return doc
+
+    def _find_data_tables(self, sheet: Worksheet):
+        """
+        Find all compact rectangular data tables in a sheet.
+        """
+
+        tables = []  # List to store found tables
+        visited: set[Tuple[int, int]] = set()  # Track already visited cells
+
+        # Iterate over all cells in the sheet
+        for ri, row in enumerate(sheet.iter_rows(values_only=False)):
+            for rj, cell in enumerate(row):
+
+                # Skip empty or already visited cells
+                if cell.value is None or (ri, rj) in visited:
+                    continue
+
+                # If the cell starts a new table, find its bounds
+                table_bounds, visited_cells = self._find_table_bounds(
+                    sheet, ri, rj, visited
+                )
+
+                visited.update(visited_cells)  # Mark these cells as visited
+                tables.append(table_bounds)
+
+        return tables
+
+    def _find_table_bounds(
+        self,
+        sheet: Worksheet,
+        start_row: int,
+        start_col: int,
+        visited: set[Tuple[int, int]],
+    ):
+        """
+        Determine the bounds of a compact rectangular table.
+        Returns:
+        - A dictionary with the bounds and data.
+        - A set of visited cell coordinates.
+        """
+        _log.info("find_table_bounds")
+
+        max_row = start_row
+        max_col = start_col
+
+        # Expand downward to find the table's bottom boundary
+        while (
+            max_row < sheet.max_row - 1
+            and sheet.cell(row=max_row + 2, column=start_col + 1).value is not None
+        ):
+            max_row += 1
+
+        # Expand rightward to find the table's right boundary
+        while (
+            max_col < sheet.max_column - 1
+            and sheet.cell(row=start_row + 1, column=max_col + 2).value is not None
+        ):
+            max_col += 1
+
+        # Collect the data within the bounds
+        data = []
+        visited_cells = set()
+        for ri in range(start_row, max_row + 1):
+
+            for rj in range(start_col, max_col + 1):
+
+                cell = sheet.cell(row=ri + 1, column=rj + 1)  # 1-based indexing
+
+                # Check if the cell belongs to a merged range
+                row_span = 1
+                col_span = 1
+                for merged_range in sheet.merged_cells.ranges:
+                    if (ri + 1, rj + 1) in merged_range:
+                        # Calculate the spans
+                        row_span = merged_range.max_row - merged_range.min_row + 1
+                        col_span = merged_range.max_col - merged_range.min_col + 1
+                        break
+
+                data.append(
+                    ExcelCell(
+                        row=ri - start_row,
+                        col=rj - start_col,
+                        text=str(cell.value),
+                        row_span=row_span,
+                        col_span=col_span,
+                    )
+                )
+
+                # Mark all cells in the span as visited
+                for span_row in range(ri, ri + row_span):
+                    for span_col in range(rj, rj + col_span):
+                        visited_cells.add((span_row, span_col))
+
+        return (
+            ExcelTable(
+                num_rows=max_row + 1 - start_row,
+                num_cols=max_col + 1 - start_col,
+                data=data,
+            ),
+            visited_cells,
+        )
+
+    def _find_images_in_sheet(
+        self, doc: DoclingDocument, sheet: Worksheet
+    ) -> DoclingDocument:
+
+        # FIXME: mypy does not agree with _images ...
+        """
+        # Iterate over images in the sheet
+        for idx, image in enumerate(sheet._images):  # Access embedded images
+
+            image_bytes = BytesIO(image.ref.blob)
+            pil_image = Image.open(image_bytes)
+
+            doc.add_picture(
+                parent=self.parents[0],
+                image=ImageRef.from_pil(image=pil_image, dpi=72),
+                caption=None,
+            )
+        """
+
+        # FIXME: mypy does not agree with _charts ...
+        """
+        for idx, chart in enumerate(sheet._charts):  # Access embedded charts
+            chart_path = f"chart_{idx + 1}.png"
+            _log.info(
+                f"Chart found, but dynamic rendering is required for: {chart_path}"
+            )
+
+            _log.info(f"Chart {idx + 1}:")
+
+            # Chart type
+            _log.info(f"Type: {type(chart).__name__}")
+
+            # Title
+            if chart.title:
+                _log.info(f"Title: {chart.title}")
+            else:
+                _log.info("No title")
+
+            # Data series
+            for series in chart.series:
+                _log.info(" => series ...")
+                _log.info(f"Data Series: {series.title}")
+                _log.info(f"Values: {series.values}")
+                _log.info(f"Categories: {series.categories}")
+
+            # Position
+            # _log.info(f"Anchor Cell: {chart.anchor}")
+        """
+
+        return doc

docling/datamodel/base_models.py

@@ -32,6 +32,7 @@ class InputFormat(str, Enum):
     PDF = "pdf"
     ASCIIDOC = "asciidoc"
     MD = "md"
+    XLSX = "xlsx"
 
 
 class OutputFormat(str, Enum):
@@ -49,6 +50,7 @@ class OutputFormat(str, Enum):
     InputFormat.HTML: ["html", "htm", "xhtml"],
     InputFormat.IMAGE: ["jpg", "jpeg", "png", "tif", "tiff", "bmp"],
     InputFormat.ASCIIDOC: ["adoc", "asciidoc", "asc"],
+    InputFormat.XLSX: ["xlsx"],
 }
 
 FormatToMimeType: Dict[InputFormat, List[str]] = {
@@ -72,7 +74,11 @@ class OutputFormat(str, Enum):
     InputFormat.PDF: ["application/pdf"],
     InputFormat.ASCIIDOC: ["text/asciidoc"],
     InputFormat.MD: ["text/markdown", "text/x-markdown"],
+    InputFormat.XLSX: [
+        "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
+    ],
 }
+
 MimeTypeToFormat = {
     mime: fmt for fmt, mimes in FormatToMimeType.items() for mime in mimes
 }

docling/document_converter.py

@@ -12,6 +12,7 @@
 from docling.backend.docling_parse_backend import DoclingParseDocumentBackend
 from docling.backend.html_backend import HTMLDocumentBackend
 from docling.backend.md_backend import MarkdownDocumentBackend
+from docling.backend.msexcel_backend import MsExcelDocumentBackend
 from docling.backend.mspowerpoint_backend import MsPowerpointDocumentBackend
 from docling.backend.msword_backend import MsWordDocumentBackend
 from docling.datamodel.base_models import ConversionStatus, DocumentStream, InputFormat
@@ -44,6 +45,11 @@ def set_optional_field_default(self) -> "FormatOption":
         return self
 
 
+class ExcelFormatOption(FormatOption):
+    pipeline_cls: Type = SimplePipeline
+    backend: Type[AbstractDocumentBackend] = MsExcelDocumentBackend
+
+
 class WordFormatOption(FormatOption):
     pipeline_cls: Type = SimplePipeline
     backend: Type[AbstractDocumentBackend] = MsWordDocumentBackend
@@ -80,6 +86,9 @@ class ImageFormatOption(FormatOption):
 
 
 _format_to_default_options = {
+    InputFormat.XLSX: FormatOption(
+        pipeline_cls=SimplePipeline, backend=MsExcelDocumentBackend
+    ),
     InputFormat.DOCX: FormatOption(
         pipeline_cls=SimplePipeline, backend=MsWordDocumentBackend
     ),