66 lines
2.3 KiB
Python
66 lines
2.3 KiB
Python
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import os
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import shutil
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import six
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from tempfile import mkdtemp
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from ..exceptions import UnknownMethod, ShellError
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from .utils import ShellParser
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from .image import Parser as TesseractParser
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class Parser(ShellParser):
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"""Extract text from pdf files using either the ``pdftotext`` method
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(default) or the ``pdfminer`` method.
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"""
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def extract(self, filename, method='', **kwargs):
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if method == '' or method == 'pdftotext':
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try:
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return self.extract_pdftotext(filename, **kwargs)
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except ShellError as ex:
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# If pdftotext isn't installed and the pdftotext method
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# wasn't specified, then gracefully fallback to using
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# pdfminer instead.
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if method == '' and ex.is_not_installed():
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return self.extract_pdfminer(filename, **kwargs)
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else:
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raise ex
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elif method == 'pdfminer':
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return self.extract_pdfminer(filename, **kwargs)
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elif method == 'tesseract':
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return self.extract_tesseract(filename, **kwargs)
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else:
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raise UnknownMethod(method)
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def extract_pdftotext(self, filename, **kwargs):
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"""Extract text from pdfs using the pdftotext command line utility."""
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if 'layout' in kwargs:
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args = ['pdftotext', '-layout', filename, '-']
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else:
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args = ['pdftotext', filename, '-']
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stdout, _ = self.run(args)
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return stdout
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def extract_pdfminer(self, filename, **kwargs):
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"""Extract text from pdfs using pdfminer."""
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stdout, _ = self.run(['pdf2txt.py', filename])
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return stdout
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def extract_tesseract(self, filename, **kwargs):
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"""Extract text from pdfs using tesseract (per-page OCR)."""
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temp_dir = mkdtemp()
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base = os.path.join(temp_dir, 'conv')
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contents = []
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try:
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stdout, _ = self.run(['pdftoppm', filename, base])
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for page in sorted(os.listdir(temp_dir)):
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page_path = os.path.join(temp_dir, page)
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page_content = TesseractParser().extract(page_path, **kwargs)
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contents.append(page_content)
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return six.b('').join(contents)
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finally:
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shutil.rmtree(temp_dir)
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