import itertools import logging from typing import Any, BinaryIO, Container, Dict, Iterator, List, Optional, Set, Tuple from pdfminer import settings from pdfminer.pdfdocument import ( PDFDocument, PDFNoPageLabels, PDFTextExtractionNotAllowed, ) from pdfminer.pdfexceptions import PDFObjectNotFound, PDFValueError from pdfminer.pdfparser import PDFParser from pdfminer.pdftypes import dict_value, int_value, list_value, resolve1 from pdfminer.psparser import LIT from pdfminer.utils import Rect, parse_rect log = logging.getLogger(__name__) # some predefined literals and keywords. LITERAL_PAGE = LIT("Page") LITERAL_PAGES = LIT("Pages") class PDFPage: """An object that holds the information about a page. A PDFPage object is merely a convenience class that has a set of keys and values, which describe the properties of a page and point to its contents. Attributes ---------- doc: a PDFDocument object. pageid: any Python object that can uniquely identify the page. attrs: a dictionary of page attributes. contents: a list of PDFStream objects that represents the page content. lastmod: the last modified time of the page. resources: a dictionary of resources used by the page. mediabox: the physical size of the page. cropbox: the crop rectangle of the page. rotate: the page rotation (in degree). annots: the page annotations. beads: a chain that represents natural reading order. label: the page's label (typically, the logical page number). """ def __init__( self, doc: PDFDocument, pageid: object, attrs: object, label: Optional[str], ) -> None: """Initialize a page object. doc: a PDFDocument object. pageid: any Python object that can uniquely identify the page. attrs: a dictionary of page attributes. label: page label string. """ self.doc = doc self.pageid = pageid self.attrs = dict_value(attrs) self.label = label self.lastmod = resolve1(self.attrs.get("LastModified")) self.resources: Dict[object, object] = resolve1( self.attrs.get("Resources", dict()), ) self.mediabox = self._parse_mediabox(self.attrs.get("MediaBox")) self.cropbox = self._parse_cropbox(self.attrs.get("CropBox"), self.mediabox) self.contents = self._parse_contents(self.attrs.get("Contents")) self.rotate = (int_value(self.attrs.get("Rotate", 0)) + 360) % 360 self.annots = self.attrs.get("Annots") self.beads = self.attrs.get("B") def __repr__(self) -> str: return f"" INHERITABLE_ATTRS = {"Resources", "MediaBox", "CropBox", "Rotate"} @classmethod def create_pages(cls, document: PDFDocument) -> Iterator["PDFPage"]: def depth_first_search( obj: Any, parent: Dict[str, Any], visited: Optional[Set[Any]] = None, ) -> Iterator[Tuple[int, Dict[Any, Dict[Any, Any]]]]: if isinstance(obj, int): object_id = obj object_properties = dict_value(document.getobj(object_id)).copy() else: # This looks broken. obj.objid means obj could be either # PDFObjRef or PDFStream, but neither is valid for dict_value. object_id = obj.objid # type: ignore[attr-defined] object_properties = dict_value(obj).copy() # Avoid recursion errors by keeping track of visited nodes if visited is None: visited = set() if object_id in visited: return visited.add(object_id) for k, v in parent.items(): if k in cls.INHERITABLE_ATTRS and k not in object_properties: object_properties[k] = v object_type = object_properties.get("Type") if object_type is None and not settings.STRICT: # See #64 object_type = object_properties.get("type") if object_type is LITERAL_PAGES and "Kids" in object_properties: log.debug("Pages: Kids=%r", object_properties["Kids"]) for child in list_value(object_properties["Kids"]): yield from depth_first_search(child, object_properties, visited) elif object_type is LITERAL_PAGE: log.debug("Page: %r", object_properties) yield (object_id, object_properties) try: page_labels: Iterator[Optional[str]] = document.get_page_labels() except PDFNoPageLabels: page_labels = itertools.repeat(None) pages = False if "Pages" in document.catalog: objects = depth_first_search(document.catalog["Pages"], document.catalog) for objid, tree in objects: yield cls(document, objid, tree, next(page_labels)) pages = True if not pages: # fallback when /Pages is missing. for xref in document.xrefs: for objid in xref.get_objids(): try: obj = document.getobj(objid) if isinstance(obj, dict) and obj.get("Type") is LITERAL_PAGE: yield cls(document, objid, obj, next(page_labels)) except PDFObjectNotFound: pass @classmethod def get_pages( cls, fp: BinaryIO, pagenos: Optional[Container[int]] = None, maxpages: int = 0, password: str = "", caching: bool = True, check_extractable: bool = False, ) -> Iterator["PDFPage"]: # Create a PDF parser object associated with the file object. parser = PDFParser(fp) # Create a PDF document object that stores the document structure. doc = PDFDocument(parser, password=password, caching=caching) # Check if the document allows text extraction. # If not, warn the user and proceed. if not doc.is_extractable: if check_extractable: error_msg = "Text extraction is not allowed: %r" % fp raise PDFTextExtractionNotAllowed(error_msg) else: warning_msg = ( "The PDF %r contains a metadata field " "indicating that it should not allow " "text extraction. Ignoring this field " "and proceeding. Use the check_extractable " "if you want to raise an error in this case" % fp ) log.warning(warning_msg) # Process each page contained in the document. for pageno, page in enumerate(cls.create_pages(doc)): if pagenos and (pageno not in pagenos): continue yield page if maxpages and maxpages <= pageno + 1: break def _parse_mediabox(self, value: Any) -> Rect: us_letter = (0.0, 0.0, 612.0, 792.0) if value is None: log.warning( "MediaBox missing from /Page (and not inherited), " "defaulting to US Letter" ) return us_letter try: return parse_rect(resolve1(val) for val in resolve1(value)) except PDFValueError: log.warning("Invalid MediaBox in /Page, defaulting to US Letter") return us_letter def _parse_cropbox(self, value: Any, mediabox: Rect) -> Rect: if value is None: log.warning("CropBox missing from /Page, defaulting to MediaBox") return mediabox try: return parse_rect(resolve1(val) for val in resolve1(value)) except PDFValueError: log.warning("Invalid CropBox in /Page, defaulting to MediaBox") return mediabox def _parse_contents(self, value: Any) -> List[Any]: contents: List[Any] = [] if value is not None: contents = resolve1(value) if not isinstance(contents, list): contents = [contents] return contents