feat: Add option to define page range (#852)

Signed-off-by: Christoph Auer <cau@zurich.ibm.com>

docling/datamodel/document.py

@@ -157,6 +157,8 @@ class InputDocument(BaseModel):
                     self.page_count = self._backend.page_count()
                     if not self.page_count <= self.limits.max_num_pages:
                         self.valid = False
+                    elif self.page_count < self.limits.page_range[0]:
+                        self.valid = False
 
         except (FileNotFoundError, OSError) as e:
             self.valid = False

docling/datamodel/settings.py

@@ -1,13 +1,28 @@
 import sys
 from pathlib import Path
+from typing import Annotated, Tuple
 
-from pydantic import BaseModel
+from pydantic import BaseModel, PlainValidator
 from pydantic_settings import BaseSettings, SettingsConfigDict
 
 
+def _validate_page_range(v: Tuple[int, int]) -> Tuple[int, int]:
+    if v[0] < 1 or v[1] < v[0]:
+        raise ValueError(
+            "Invalid page range: start must be ≥ 1 and end must be ≥ start."
+        )
+    return v
+
+
+PageRange = Annotated[Tuple[int, int], PlainValidator(_validate_page_range)]
+
+DEFAULT_PAGE_RANGE: PageRange = (1, sys.maxsize)
+
+
 class DocumentLimits(BaseModel):
     max_num_pages: int = sys.maxsize
     max_file_size: int = sys.maxsize
+    page_range: PageRange = DEFAULT_PAGE_RANGE
 
 
 class BatchConcurrencySettings(BaseModel):

docling/document_converter.py

@@ -1,9 +1,10 @@
 import logging
+import math
 import sys
 import time
 from functools import partial
 from pathlib import Path
-from typing import Dict, Iterable, Iterator, List, Optional, Type, Union
+from typing import Dict, Iterable, Iterator, List, Optional, Tuple, Type, Union
 
 from pydantic import BaseModel, ConfigDict, model_validator, validate_call
 
@@ -31,7 +32,12 @@ from docling.datamodel.document import (
     _DocumentConversionInput,
 )
 from docling.datamodel.pipeline_options import PipelineOptions
-from docling.datamodel.settings import DocumentLimits, settings
+from docling.datamodel.settings import (
+    DEFAULT_PAGE_RANGE,
+    DocumentLimits,
+    PageRange,
+    settings,
+)
 from docling.exceptions import ConversionError
 from docling.pipeline.base_pipeline import BasePipeline
 from docling.pipeline.simple_pipeline import SimplePipeline
@@ -184,6 +190,7 @@ class DocumentConverter:
         raises_on_error: bool = True,
         max_num_pages: int = sys.maxsize,
         max_file_size: int = sys.maxsize,
+        page_range: PageRange = DEFAULT_PAGE_RANGE,
     ) -> ConversionResult:
         all_res = self.convert_all(
             source=[source],
@@ -191,6 +198,7 @@ class DocumentConverter:
             max_num_pages=max_num_pages,
             max_file_size=max_file_size,
             headers=headers,
+            page_range=page_range,
         )
         return next(all_res)
 
@@ -202,10 +210,12 @@ class DocumentConverter:
         raises_on_error: bool = True,  # True: raises on first conversion error; False: does not raise on conv error
         max_num_pages: int = sys.maxsize,
         max_file_size: int = sys.maxsize,
+        page_range: PageRange = DEFAULT_PAGE_RANGE,
     ) -> Iterator[ConversionResult]:
         limits = DocumentLimits(
             max_num_pages=max_num_pages,
             max_file_size=max_file_size,
+            page_range=page_range,
         )
         conv_input = _DocumentConversionInput(
             path_or_stream_iterator=source, limits=limits, headers=headers

docling/pipeline/base_pipeline.py

@@ -141,7 +141,9 @@ class PaginatedPipeline(BasePipeline):  # TODO this is a bad name.
         with TimeRecorder(conv_res, "doc_build", scope=ProfilingScope.DOCUMENT):
 
             for i in range(0, conv_res.input.page_count):
-                conv_res.pages.append(Page(page_no=i))
+                start_page, end_page = conv_res.input.limits.page_range
+                if (start_page - 1) <= i <= (end_page - 1):
+                    conv_res.pages.append(Page(page_no=i))
 
             try:
                 # Iterate batches of pages (page_batch_size) in the doc

tests/test_input_doc.py

@@ -4,6 +4,7 @@ from pathlib import Path
 from docling.backend.pypdfium2_backend import PyPdfiumDocumentBackend
 from docling.datamodel.base_models import DocumentStream, InputFormat
 from docling.datamodel.document import InputDocument, _DocumentConversionInput
+from docling.datamodel.settings import DocumentLimits
 
 
 def test_in_doc_from_valid_path():
@@ -39,6 +40,40 @@ def test_in_doc_from_invalid_buf():
     assert doc.valid == False
 
 
+def test_in_doc_with_page_range():
+    test_doc_path = Path("./tests/data/2206.01062.pdf")
+    limits = DocumentLimits()
+    limits.page_range = (1, 10)
+
+    doc = InputDocument(
+        path_or_stream=test_doc_path,
+        format=InputFormat.PDF,
+        backend=PyPdfiumDocumentBackend,
+        limits=limits,
+    )
+    assert doc.valid == True
+
+    limits.page_range = (9, 9)
+
+    doc = InputDocument(
+        path_or_stream=test_doc_path,
+        format=InputFormat.PDF,
+        backend=PyPdfiumDocumentBackend,
+        limits=limits,
+    )
+    assert doc.valid == True
+
+    limits.page_range = (11, 12)
+
+    doc = InputDocument(
+        path_or_stream=test_doc_path,
+        format=InputFormat.PDF,
+        backend=PyPdfiumDocumentBackend,
+        limits=limits,
+    )
+    assert doc.valid == False
+
+
 def test_guess_format(tmp_path):
     """Test docling.datamodel.document._DocumentConversionInput.__guess_format"""
     dci = _DocumentConversionInput(path_or_stream_iterator=[])

tests/test_options.py

@@ -105,6 +105,20 @@ def test_e2e_conversions(test_doc_path):
         assert doc_result.status == ConversionStatus.SUCCESS
 
 
+def test_page_range(test_doc_path):
+    converter = DocumentConverter()
+    doc_result: ConversionResult = converter.convert(test_doc_path, page_range=(9, 9))
+
+    assert doc_result.status == ConversionStatus.SUCCESS
+    assert doc_result.input.page_count == 9
+    assert doc_result.document.num_pages() == 1
+
+    doc_result: ConversionResult = converter.convert(
+        test_doc_path, page_range=(10, 10), raises_on_error=False
+    )
+    assert doc_result.status == ConversionStatus.FAILURE
+
+
 def test_ocr_coverage_threshold(test_doc_path):
     pipeline_options = PdfPipelineOptions()
     pipeline_options.do_ocr = True