在 python 中使用 PDFMiner 从 PDF 文件中提取文本？

我正在寻找关于如何使用 PDFMiner 和 Python 从 PDF 文件中提取文本的 或者文档示例。

看起来 PDFMiner 更新了他们的 API，我发现所有相关的示例都包含过时的代码(类和方法已经更改)。我发现，使从 PDF 文件中提取文本的任务更容易的库使用的是旧的 PDFMiner 语法，所以我不确定如何做到这一点。

实际上，我只是在查看源代码，看看是否能够解决这个问题。

189684 次浏览
小开
最佳答案

Here is a working example of extracting text from a PDF file using the current version of PDFMiner(September 2016) 

from pdfminer.pdfinterp import PDFResourceManager, PDFPageInterpreter
from pdfminer.converter import TextConverter
from pdfminer.layout import LAParams
from pdfminer.pdfpage import PDFPage
from io import StringIO


def convert_pdf_to_txt(path):
rsrcmgr = PDFResourceManager()
retstr = StringIO()
codec = 'utf-8'
laparams = LAParams()
device = TextConverter(rsrcmgr, retstr, codec=codec, laparams=laparams)
fp = open(path, 'rb')
interpreter = PDFPageInterpreter(rsrcmgr, device)
password = ""
maxpages = 0
caching = True
pagenos=set()


for page in PDFPage.get_pages(fp, pagenos, maxpages=maxpages, password=password,caching=caching, check_extractable=True):
interpreter.process_page(page)


text = retstr.getvalue()


fp.close()
device.close()
retstr.close()
return text

PDFMiner's structure changed recently, so this should work for extracting text from the PDF files.

Edit : Still working as of the June 7th of 2018. Verified in Python Version 3.x

Edit: The solution works with Python 3.7 at October 3, 2019. I used the Python library pdfminer.six, released on November 2018.

小开

terrific answer from DuckPuncher, for Python3 make sure you install pdfminer2 and do:

import io


from pdfminer.pdfinterp import PDFResourceManager, PDFPageInterpreter
from pdfminer.converter import TextConverter
from pdfminer.layout import LAParams
from pdfminer.pdfpage import PDFPage




def convert_pdf_to_txt(path):
rsrcmgr = PDFResourceManager()
retstr = io.StringIO()
codec = 'utf-8'
laparams = LAParams()
device = TextConverter(rsrcmgr, retstr, codec=codec, laparams=laparams)
fp = open(path, 'rb')
interpreter = PDFPageInterpreter(rsrcmgr, device)
password = ""
maxpages = 0
caching = True
pagenos = set()


for page in PDFPage.get_pages(fp, pagenos, maxpages=maxpages,
password=password,
caching=caching,
check_extractable=True):
interpreter.process_page(page)






fp.close()
device.close()
text = retstr.getvalue()
retstr.close()
return text
小开

this code is tested with pdfminer for python 3 (pdfminer-20191125)

from pdfminer.layout import LAParams
from pdfminer.converter import PDFPageAggregator
from pdfminer.pdfinterp import PDFResourceManager
from pdfminer.pdfinterp import PDFPageInterpreter
from pdfminer.pdfpage import PDFPage
from pdfminer.layout import LTTextBoxHorizontal


def parsedocument(document):
# convert all horizontal text into a lines list (one entry per line)
# document is a file stream
lines = []
rsrcmgr = PDFResourceManager()
laparams = LAParams()
device = PDFPageAggregator(rsrcmgr, laparams=laparams)
interpreter = PDFPageInterpreter(rsrcmgr, device)
for page in PDFPage.get_pages(document):
interpreter.process_page(page)
layout = device.get_result()
for element in layout:
if isinstance(element, LTTextBoxHorizontal):
lines.extend(element.get_text().splitlines())
return lines
小开

Full disclosure, I am one of the maintainers of pdfminer.six. It is a community-maintained version of pdfminer for python 3.

Nowadays, it has multiple api's to extract text from a PDF, depending on your needs. Behind the scenes, all of these api's use the same logic for parsing and analyzing the layout.

(All the examples assume your PDF file is called example.pdf)

Commandline

If you want to extract text just once you can use the commandline tool pdf2txt.py:

$ pdf2txt.py example.pdf

High-level api

If you want to extract text (properties) with Python, you can use the high-level api. This approach is the go-to solution if you want to programmatically extract information from a PDF.

from pdfminer.high_level import extract_text


# Extract text from a pdf.
text = extract_text('example.pdf')


# Extract iterable of LTPage objects.
pages = extract_pages('example.pdf')

Composable api

There is also a composable api that gives a lot of flexibility in handling the resulting objects. For example, it allows you to create your own layout algorithm. This method is suggested in the other answers, but I would only recommend this when you need to customize some component.

from io import StringIO


from pdfminer.converter import TextConverter
from pdfminer.layout import LAParams
from pdfminer.pdfdocument import PDFDocument
from pdfminer.pdfinterp import PDFResourceManager, PDFPageInterpreter
from pdfminer.pdfpage import PDFPage
from pdfminer.pdfparser import PDFParser


output_string = StringIO()
with open('example.pdf', 'rb') as in_file:
parser = PDFParser(in_file)
doc = PDFDocument(parser)
rsrcmgr = PDFResourceManager()
device = TextConverter(rsrcmgr, output_string, laparams=LAParams())
interpreter = PDFPageInterpreter(rsrcmgr, device)
for page in PDFPage.create_pages(doc):
interpreter.process_page(page)


print(output_string.getvalue())

Similar question and answer here. I'll try to keep them in sync.

小开

This works in May 2020 using PDFminer six in Python3.

Installing the package

$ pip install pdfminer.six

Importing the package

from pdfminer.high_level import extract_text

Using a PDF saved on disk

text = extract_text('report.pdf')

Or alternatively:

with open('report.pdf','rb') as f:
text = extract_text(f)

Using PDF already in memory

If the PDF is already in memory, for example if retrieved from the web with the requests library, it can be converted to a stream using the io library:

import io


response = requests.get(url)
text = extract_text(io.BytesIO(response.content))

Performance and Reliability compared with PyPDF2

PDFminer.six works more reliably than PyPDF2 (which fails with certain types of PDFs), in particular PDF version 1.7

However, text extraction with PDFminer.six is significantly slower than PyPDF2 by a factor of 6.

I timed text extraction with timeit on a 15" MBP (2018), timing only the extraction function (no file opening etc.) with a 10 page PDF and got the following results:

PDFminer.six: 2.88 sec
PyPDF2:       0.45 sec

pdfminer.six also has a huge footprint, requiring pycryptodome which needs GCC and other things installed pushing a minimal install docker image on Alpine Linux from 80 MB to 350 MB. PyPDF2 has no noticeable storage impact.

Update (2022-08-04): According to Martin Thoma, PyPDF2 has improved a lot in the past 2 years, so do give it a try as well. Here's his benchmark

小开

I realize that this is an old question. For anyone trying to use pdfminer, you should switch to pdfminer.six which is the currently maintained version.


提交答案