134 lines
4.9 KiB
Python
134 lines
4.9 KiB
Python
"""
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This files contains all the functions to extract DOIs of citations from
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PDF files.
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"""
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import requests
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import subprocess
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import xml.etree.ElementTree as ET
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from requests.exceptions import RequestException
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from libbmc.citations import plaintext
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CERMINE_BASE_URL = "http://cermine.ceon.pl/"
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def cermine(pdf_file):
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"""
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Run `CERMINE <https://github.com/CeON/CERMINE>`_ to extract procedure on \
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the given PDF file, to retrieve citations (and more) from the \
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provided PDF file.
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.. note::
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This uses the `CERMINE API <http://cermine.ceon.pl/about.html>`_, and \
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hence, uploads the PDF file (so uses network). Check out \
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the CERMINE API terms.
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:param pdf_file: Path to the PDF file to handle.
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:returns: Raw output from CERMINE API or ``None`` if an error occurred. \
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No post-processing is done.
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"""
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try:
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with open(pdf_file, "rb") as fh:
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r = requests.post(
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CERMINE_BASE_URL + "extract.do",
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headers={"Content-Type": "application/binary"},
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files={"file": fh}
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)
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return r.text
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except (RequestException, FileNotFoundError):
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return None
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def grobid(pdf_file):
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"""
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Run `Grobid <https://github.com/kermitt2/grobid>`_ on a given PDF file to \
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extract references.
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.. note::
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Before using this function, you have to download and build Grobid on \
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your system. See \
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`<https://grobid.readthedocs.org/en/latest/Install-Grobid/>`_ \
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for more infos on this. You need Java and \
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``grobid-core-`<current version>`.one-jar.jar`` to be in your \
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``$PATH``.
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:param pdf_file: Path to the PDF file to handle.
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:returns: Raw output from ``Grobid`` or ``None`` if an error occurred.
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"""
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# TODO + update docstring
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# TODO: Use https://github.com/kermitt2/grobid-example
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subprocess.check_output(["java",
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"-jar", "grobid-core-0.3.0.one-jar.jar",
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"-Xmx1024m", # Avoid OutOfMemoryException
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"-gH", "/path/to/Grobid/grobid/grobid-home",
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"-gP", "/path/to/Grobid/grobid-home/config/grobid.properties",
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"-dIn", "/path/to/input/directory",
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"-dOut", "/path/to/output/directory",
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"-exe", "processReferences"])
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def pdfextract(pdf_file):
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"""
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Run `pdfextract <https://github.com/CrossRef/pdfextract>`_ on a given PDF \
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file to extract references.
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.. note::
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Before using this function, you have to install pdfextract on \
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your system. See \
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`<https://github.com/CrossRef/pdfextract#quick-start>`_ \
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for more infos on this. You need the ``pdf-extract`` command \
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to be in your ``$PATH``. This can be done easily using \
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``gem install pdf-extract``, provided that you have a correct \
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Ruby install on your system.
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.. note::
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``pdfextract`` is full a bugs and as the time of writing this, \
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you had to manually ``gem install pdf-reader -v 1.2.0`` \
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before installing ``pdfextract`` or you would get errors. See \
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`this Github issue <https://github.com/CrossRef/pdfextract/issues/23>`_.
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:param pdf_file: Path to the PDF file to handle.
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:returns: Raw output from ``pdfextract`` or ``None`` if an error \
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occurred. No post-processing is done. See \
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``libbmc.citations.pdf.pdfextract_dois`` for a similar function \
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with post-processing to return DOIs.
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"""
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try:
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# Run pdf-extract
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references = subprocess.check_output(["pdf-extract",
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"extract", "--references",
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pdf_file])
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return references
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except subprocess.CalledProcessError:
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return None
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def pdfextract_dois(pdf_file):
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"""
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Extract DOIs of references using \
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`pdfextract <https://github.com/CrossRef/pdfextract>`_.
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.. note::
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See ``libbmc.citations.pdf.pdfextract`` function as this one is just \
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a wrapper around it.
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See ``libbmc.citations.plaintext.get_cited_dois`` as well for the \
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returned value, as it is ultimately called by this function.
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:param pdf_file: Path to the PDF file to handle.
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:returns: A dict of cleaned plaintext citations and their associated DOI.
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"""
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# Call pdf-extract on the PDF file
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references = pdfextract(pdf_file)
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# Parse the resulting XML
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root = ET.fromstring(references)
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plaintext_references = [e.text for e in root.iter("reference")]
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# Call the plaintext methods to fetch DOIs
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return plaintext.get_cited_DOIs(plaintext_references)
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