first msexcel backend

Signed-off-by: Peter Staar <taa@zurich.ibm.com>

docling/backend/msexcel_backend.py

@@ -4,6 +4,8 @@ from pathlib import Path
 from typing import Set, Union
 
 from lxml import etree
+from openpyxl import load_workbook
+from openpyxl.cell.cell import Cell
 
 from docling.backend.abstract_backend import DeclarativeDocumentBackend
 from docling.datamodel.base_models import InputFormat
@@ -16,7 +18,30 @@ 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 = {}  # type: ignore
+        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:
         return self.valid
 
@@ -39,18 +64,161 @@ class MsExcelDocumentBackend(DeclarativeDocumentBackend):
 
         origin = DocumentOrigin(
             filename=self.file.name or "file",
-            mimetype="application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+            mimetype="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
             binary_hash=self.document_hash,
         )
 
-        doc = DoclingDocument(name=self.file.stem or "file", origin=origin)
         if self.is_valid():
-            # FIXME: do implementation
-            return doc
+            return self.convert_workbook(doc)
         else:
             raise RuntimeError(
                 f"Cannot convert doc with {self.document_hash} because the backend failed to init."
             )
 
+        return DoclingDocument(name=self.file.stem or "file", origin=origin)
 
-        
+    def get_level(self) -> int:
+        """Return the first None index."""
+        for k, v in self.parents.items():
+            if k >= 0 and v == None:
+                return k
+        return 0
+
+    def convert_workbook(self) -> DoclingDocument:
+
+        doc = DoclingDocument(name=self.file.stem or "file", origin=origin)
+
+        # Iterate over all sheets
+        for sheet_name in workbook.sheetnames:
+            _log.info(f"Processing sheet: {sheet_name}")
+            sheet = workbook[sheet_name]  # Access the sheet by name
+
+            # level = self.get_level()
+
+            self.parents[0] = doc.add_group(
+                parent=None,  # self.parents[level-1],
+                label=GroupLabel.SECTION,
+                name=f"sheet: {sheet_name}",
+            )
+
+            self.convert_sheet(doc, sheet)
+
+    def convert_sheet(self, doc: DoclingDocument, sheet):
+
+        tables = self.find_data_tables(sheet)
+
+        for excel_table in tables:
+
+            table_data = TableData(
+                num_rows=excel_table["num_rows"],
+                num_cols=excel_table["num_cols"],
+                table_cells=[],
+            )
+
+            for excel_cell in excel_table["data"]:
+                cell = TableCell(
+                    text=str(excel_cell.value),
+                    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,  # col_header,
+                    row_header=False,  # ((not col_header) and html_cell.name=='th')
+                )
+                data.table_cells.append(cell)
+
+            doc.append_table(data=table_data, parent=self.parents[0])
+
+    def find_data_tables(self, sheet):
+        """
+        Find all compact rectangular data tables in a sheet.
+        """
+        tables = []  # List to store found tables
+        visited = 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 = 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, start_row, start_col, visited):
+        """
+        Determine the bounds of a compact rectangular table.
+        Returns:
+        - A dictionary with the bounds and data.
+        - A set of visited cell coordinates.
+        """
+        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):
+            row_data = []
+            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
+
+                # Register the cell with spans
+                row_data.append(
+                    {
+                        "row": ri - start_row,
+                        "col": rj - start_col,
+                        "cell": cell,
+                        "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))
+
+            data.append(row_data)
+
+        return {
+            "beg_row": start_row,
+            "beg_col": start_col,
+            "end_row": max_row,
+            "end_col": max_col,
+            "num_rows": max_row - start_row,
+            "num_cols": max_col - start_col,
+            "data": data,
+        }, visited_cells

docling/datamodel/base_models.py

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