Extract Text Using PdfMiner and PyPDF2 Merges columns - python

I am trying to parse the pdf file text using pdfMiner, but the extracted text gets merged. I am using the pdf file from the following link [edit: link was broken / pointed to potential malware]
I am good with any type of output (file/string). Here is the code which returns the extracted text as string for me but for some reason, columns are merged.
from pdfminer.converter import TextConverter
from pdfminer.layout import LAParams
from pdfminer.pdfinterp import PDFResourceManager, process_pdf
import StringIO
def convert_pdf(filename):
rsrcmgr = PDFResourceManager()
retstr = StringIO()
codec = 'utf-8'
laparams = LAParams()
device = TextConverter(rsrcmgr, retstr, codec=codec)
fp = file(filename, 'rb')
process_pdf(rsrcmgr, device, fp)
fp.close()
device.close()
str = retstr.getvalue()
retstr.close()
return str
I have also tried PyPdf2, but faced the same issue. Here is the sample code for PyPDF2
from PyPDF2 import PdfReader
import StringIO
def get_data_using_pypdf2(filename):
reader = PdfReader(filename)
content = ""
for page in reader.pages:
extracted_text = page.extract_text()
content += extracted_text + "\n"
content = " ".join(content.replace("\xa0", " ").strip().split())
return content.encode("ascii", "ignore")
I have also tried pdf2txt.py but unable to get the formatted output.

I recently struggled with a similar problem, although my pdf had slightly simpler structure.
PDFMiner uses classes called "devices" to parse the pages in a pdf fil. The basic device class is the PDFPageAggregator class, which simply parses the text boxes in the file. The converter classes , e.g. TextConverter, XMLConverter, and HTMLConverter also output the result in a file (or in a string stream as in your example) and do some more elaborate parsing for the contents.
The problem with TextConverter (and PDFPageAggregator) is that they don't recurse deep enough to the structure of the document to properly extract the different columns. The two other converters require some information about the structure of the document for display purposes, so they gather more detailed data. In your example pdf both of the simplistic devices only parse (roughly) the entire text box containing the columns, which makes it impossible (or at least very difficult) to correctly separate the different rows. The solution to this that I found works pretty well, is to either
Create a new class that inherits from PDFPageAggregator, or
Use XMLConverter and parse the resulting XML document using e.g. Beautifulsoup
In both cases you would have to combine the different text segments to rows using their bounding box y-coordinates.
In the case of a new device class ('tis more eloquent, I think) you would have to override the method receive_layout that get's called for each page during the rendering process. This method then recursively parses the elements in each page. For example, something like this might get you started:
from pdfminer.pdfdocument import PDFDocument, PDFNoOutlines
from pdfminer.pdfparser import PDFParser
from pdfminer.pdfinterp import PDFResourceManager, PDFPageInterpreter
from pdfminer.converter import PDFPageAggregator
from pdfminer.layout import LTPage, LTChar, LTAnno, LAParams, LTTextBox, LTTextLine
class PDFPageDetailedAggregator(PDFPageAggregator):
def __init__(self, rsrcmgr, pageno=1, laparams=None):
PDFPageAggregator.__init__(self, rsrcmgr, pageno=pageno, laparams=laparams)
self.rows = []
self.page_number = 0
def receive_layout(self, ltpage):
def render(item, page_number):
if isinstance(item, LTPage) or isinstance(item, LTTextBox):
for child in item:
render(child, page_number)
elif isinstance(item, LTTextLine):
child_str = ''
for child in item:
if isinstance(child, (LTChar, LTAnno)):
child_str += child.get_text()
child_str = ' '.join(child_str.split()).strip()
if child_str:
row = (page_number, item.bbox[0], item.bbox[1], item.bbox[2], item.bbox[3], child_str) # bbox == (x1, y1, x2, y2)
self.rows.append(row)
for child in item:
render(child, page_number)
return
render(ltpage, self.page_number)
self.page_number += 1
self.rows = sorted(self.rows, key = lambda x: (x[0], -x[2]))
self.result = ltpage
In the code above, each found LTTextLine element is stored in an ordered list of tuples containing the page number, coordinates of the bounding box, and the text contained in that particular element. You would then do something similar to this:
from pprint import pprint
from pdfminer.pdfparser import PDFParser
from pdfminer.pdfdocument import PDFDocument
from pdfminer.pdfpage import PDFPage
from pdfminer.pdfinterp import PDFResourceManager, PDFPageInterpreter
from pdfminer.layout import LAParams
fp = open('pdf_doc.pdf', 'rb')
parser = PDFParser(fp)
doc = PDFDocument(parser)
doc.initialize('password') # leave empty for no password
rsrcmgr = PDFResourceManager()
laparams = LAParams()
device = PDFPageDetailedAggregator(rsrcmgr, laparams=laparams)
interpreter = PDFPageInterpreter(rsrcmgr, device)
for page in PDFPage.create_pages(doc):
interpreter.process_page(page)
# receive the LTPage object for this page
device.get_result()
pprint(device.rows)
The variable device.rows contains the ordered list with all the text lines arranged using their page number and y-coordinates. You can loop over the text lines and group lines with the same y-coordinates to form the rows, store the column data etc.
I tried to parse your pdf using the above code and the columns are mostly parsed correctly. However, some of the columns are so close together that the default PDFMiner heuristics fail to separate them into their own elements. You can probably get around this by tweaking the word margin parameter (the -W flag in the command line tool pdf2text.py). In any case, you might want to read through the (poorly documented) PDFMiner API as well as browse through the source code of PDFMiner, which you can obtain from github. (Alas, I cannot paste the link because I do not have sufficient rep points :'<, but you can hopefully google the correct repo)

I tried your first block of code and got a bunch of results that look like this:
MULTIPLE DWELLING AGARDEN COMPLEX 14945010314370 TO 372WILLOWRD W MULTIPLE DWELLING AGARDEN COMPLEX 14945010314380 TO 384WILLOWRD W MULTIPLE DWELLING AGARDEN COMPLEX 149450103141000 TO 1020WILLOWBROOKRD MULTIPLE DWELLING AROOMING HOUSE 198787
I am guessing you are in a similar position as this answer and that all the whitespace is used to position the words in the proper place, not as actual printable space characters. The fact that you have tried with with other pdf libraries makes me think that this might be an issue that is difficult for any pdf library to parse.

Solution provided by #hlindblo gave pretty good results. To further group the extracted text chunks by page and paragraph, here are the simple commands I used.
from collections import OrderedDict
grouped_text = OrderedDict()
for p in range(1000): # max page nb is 1000
grouped_text[p] = {}
for (page_nb, x_min, y_min, x_max, y_max, text) in device.rows:
x_min = round(x_min)//10 # manipulate the level of aggregation --> x_min might be slitghly different
try:
grouped_text[page_nb][x_min]+= " " + text
except:
grouped_text[page_nb][x_min] = text

Related

How to get text from local PDF file using Python

Please do not use "tika" for an answer.
I have already tried answers from this question:
How to extract text from a PDF file?
I have this PDF file, https://drive.google.com/file/d/1aUfQAlvq5hA9kz2c9CyJADiY3KpY3-Vn/view?usp=sharing , and I would like to copy the text.
import PyPDF2
pdfFileObject = open('C:\\Path\\To\\Local\\File\\Test_PDF.pdf', 'rb')
pdfReader = PyPDF2.PdfFileReader(pdfFileObject)
count = pdfReader.numPages
for i in range(count):
page = pdfReader.getPage(i)
print(page.extractText())
The output is "Date Submitted: 2019-10-21 16:03:36.093 | Form Key: 5544" which is only part of the text. The next line of text starts with "Exhibit A to RFA...."
I have never used PYPDF2 myself so can't really input my knowledge to find out exactly what's going wrong. But the following from the documentation states the following about the function extractText()
Locate all text drawing commands, in the order they are provided in the content stream, and extract the text. This works well for some PDF files, but poorly for others, depending on the generator used. This will be refined in the future. Do not rely on the order of text coming out of this function, as it will change if this function is made more sophisticated.
Here's an alternative way to get around this and also exaplains what maybe going wrong. I would also recommend using pdftotext. This has worked reliably for me many times; this answer will also prove helpful in that.
Found a solution.
#pip install pdfminer.six
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):
'''Convert pdf content from a file path to text
:path the file path
'''
rsrcmgr = PDFResourceManager()
codec = 'utf-8'
laparams = LAParams()
with io.StringIO() as retstr:
with TextConverter(rsrcmgr, retstr, codec=codec,
laparams=laparams) as device:
with open(path, 'rb') as fp:
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)
return retstr.getvalue()
if __name__ == "__main__":
print(convert_pdf_to_txt('C:\\Path\\To\\Test_PDF.pdf'))

PDFMiner TypeError: not all arguments converted during string formatting

I have been trying to come up with a solution to parse a PDF into an HTML so, later I'll use beautiful soup to extract all the headings, subitems and paragraph respectively in a tree structure.
I have searched a few options available on the internet but so far no success. Here's a code I've used to parse a PDF to HTML using PDFMiner.six
import sys
from pdfminer.pdfdocument import PDFDocument
from pdfminer.layout import LTContainer, LTComponent, LTRect, LTLine, LAParams, LTTextLine
from pdfminer.pdfparser import PDFParser
from pdfminer.pdfinterp import PDFResourceManager, PDFPageInterpreter
from pdfminer.pdfdevice import PDFDevice, TagExtractor
from pdfminer.pdfpage import PDFPage
from pdfminer.converter import XMLConverter, HTMLConverter, TextConverter
from pdfminer.image import ImageWriter
from io import StringIO, BytesIO
from bs4 import BeautifulSoup
import re
import io
def convert_pdf_to_html(path):
rsrcmgr = PDFResourceManager()
retstr = StringIO()
outfp = BytesIO()
codec = 'utf-8'
laparams = LAParams()
device = HTMLConverter(rsrcmgr, outfp, imagewriter=ImageWriter('out'))
fp = open(path, 'rb')
interpreter = PDFPageInterpreter(rsrcmgr, device)
password = ""
maxpages = 0 #is for all
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()
str = retstr.getvalue()
retstr.close()
return str
convert_pdf_to_html('PDF - Remraam Ph 1 Mosque.pdf')
However, the above code returns the following error which I'm unable to fix, would appreciate any help, thank you.
~\AppData\Local\Continuum\anaconda3\lib\site-packages\pdfminer\pdftypes.py in decode(self)
293 data = ccittfaxdecode(data, params)
294 elif f == LITERAL_CRYPT:
--> 295 raise PDFNotImplementedError('Crypt filter is unsupported')
296 else:
297 raise PDFNotImplementedError('Unsupported filter: %r' % f)
TypeError: not all arguments converted during string formatting
The pdfminer.six package does not support pdf's with a Crypt filter. It does support other encryption methods. The difference with the Crypt filter is that this one defines the decription algorithm as a parameters, instead of a fixed filter.
From the Pdf reference manual:
The Crypt filter (PDF 1.5) allows the document-level security handler (see Section 3.5, “Encryption”) to determine which algorithms should be used to decrypt the input data. The Name parameter in the decode parameters dictionary for this
filter (see Table 3.12) specifies which of the named crypt filters in the document
(see Section 3.5.4, “Crypt Filters”) should be used.
If you need this feature you can create a github issue.
A quick update, I have fixed this issue, by just uninstalling and installing the Anaconda and then I've installed the pdfminer.six by coda. I guess the pip install doesn't work properly for me. Any way install the package using coda install .. package name

PDFMiner conditional extraction of text

So I've just played around with PDFMiner and can now extract text from a PDF and throw it into an html or textfile.
pdf2txt.py -o outputfile.txt -t txt inputfile.pdf
I have then written a simple script to extract all certain strings:
with open('output.txt', 'r') as searchfile:
for line in searchfile:
if 'HELLO' in line:
print(line)
And now I can use all these strings containing the word HELLO to add to my databse if that is what I wanted.
My questions is:
Is the only way or can PDFinder grab conditional stuff before even spitting it out to the txt, html or even straight into the database?
Well, yes, you can: PDFMiner has API.
The basic example sais
from pdfminer.pdfparser import PDFParser
from pdfminer.pdfdocument import PDFDocument
from pdfminer.pdfpage import PDFPage
from pdfminer.pdfpage import PDFTextExtractionNotAllowed
from pdfminer.pdfinterp import PDFResourceManager
from pdfminer.pdfinterp import PDFPageInterpreter
from pdfminer.pdfdevice import PDFDevice
# Open a PDF file.
fp = open('mypdf.pdf', 'rb')
# Create a PDF parser object associated with the file object.
parser = PDFParser(fp)
# Create a PDF document object that stores the document structure.
# Supply the password for initialization.
document = PDFDocument(parser, password)
# Check if the document allows text extraction. If not, abort.
if not document.is_extractable:
raise PDFTextExtractionNotAllowed
# Create a PDF resource manager object that stores shared resources.
rsrcmgr = PDFResourceManager()
# Create a PDF device object.
device = PDFDevice(rsrcmgr)
# Create a PDF interpreter object.
interpreter = PDFPageInterpreter(rsrcmgr, device)
# Process each page contained in the document.
for page in PDFPage.create_pages(document):
interpreter.process_page(page)
# do stuff with the page here
and in the loop you should go with
# receive the LTPage object for the page.
layout = device.get_result()
and then use LTTextBox object. You have to analyse that. There's no full example in the docs, but you may check out the pdf2txt.py source which will help you to find missing pieces (although it does much more since it parses options and applies them).
And once you have the code that extracts the text, you can do what you want before saving a file. Including searching for certain parts of text.
PS looks like this was, in a way, asked before: How do I use pdfminer as a library which should be helpful, too.

Python PDF Mining Get Position of Text on Every Line

I am currently using the class provided in the answer here:
How to extract text and text coordinates from a pdf file?
The class provided is very helpful in that I can get the position of every text box in a PDF. The class given also inserts a '_' every time there is a new line within the textbox.
I was wondering whether there was some way to get the position of each line of text within the textbox as well?
Found it: The solution is to recurse even when there is a TextBox, until a textline is found. The class below should provide the x and y coordinates of every line of text on a pdf when the parsepdf method is called.
from pdfminer.pdfparser import PDFParser
from pdfminer.pdfdocument import PDFDocument
from pdfminer.pdfpage import PDFPage
from pdfminer.pdfpage import PDFTextExtractionNotAllowed
from pdfminer.pdfinterp import PDFResourceManager
from pdfminer.pdfinterp import PDFPageInterpreter
from pdfminer.pdfdevice import PDFDevice
from pdfminer.layout import LAParams
from pdfminer.converter import PDFPageAggregator
import pdfminer
class pdfPositionHandling:
def parse_obj(self, lt_objs):
# loop over the object list
for obj in lt_objs:
if isinstance(obj, pdfminer.layout.LTTextLine):
print "%6d, %6d, %s" % (obj.bbox[0], obj.bbox[1], obj.get_text().replace('\n', '_'))
# if it's a textbox, also recurse
if isinstance(obj, pdfminer.layout.LTTextBoxHorizontal):
self.parse_obj(obj._objs)
# if it's a container, recurse
elif isinstance(obj, pdfminer.layout.LTFigure):
self.parse_obj(obj._objs)
def parsepdf(self, filename, startpage, endpage):
# Open a PDF file.
fp = open(filename, 'rb')
# Create a PDF parser object associated with the file object.
parser = PDFParser(fp)
# Create a PDF document object that stores the document structure.
# Password for initialization as 2nd parameter
document = PDFDocument(parser)
# Check if the document allows text extraction. If not, abort.
if not document.is_extractable:
raise PDFTextExtractionNotAllowed
# Create a PDF resource manager object that stores shared resources.
rsrcmgr = PDFResourceManager()
# Create a PDF device object.
device = PDFDevice(rsrcmgr)
# BEGIN LAYOUT ANALYSIS
# Set parameters for analysis.
laparams = LAParams()
# Create a PDF page aggregator object.
device = PDFPageAggregator(rsrcmgr, laparams=laparams)
# Create a PDF interpreter object.
interpreter = PDFPageInterpreter(rsrcmgr, device)
i = 0
# loop over all pages in the document
for page in PDFPage.create_pages(document):
if i >= startpage and i <= endpage:
# read the page into a layout object
interpreter.process_page(page)
layout = device.get_result()
# extract text from this object
self.parse_obj(layout._objs)
i += 1

Batch splitting PDFs by first table of contents level?

I'm looking to extract texts from PDFs for a data-mining task.
The PDFs I'm looking at contain multiple reports, each report has its own first level entry in the documents table of contents. Also, there is a written table of contents at the beginning of the PDF, which contains page numbers for each report ("from page - to page").
I'm looking for a way to either:
Split the PDF into the individual reports, in order to dump each of those into a .txt file.
Dump each section of the PDF into a .txt directly.
So far, I have been able to dump to entire file into a .txt using PDFminer (python), as follows:
# Not all imports are needed for this task
from pdfminer.pdfparser import PDFParser
from pdfminer.pdfdocument import PDFDocument
import sys
from pdfminer.pdfinterp import PDFResourceManager, PDFPageInterpreter
from pdfminer.pdfpage import PDFPage
from pdfminer.converter import XMLConverter, HTMLConverter, TextConverter
from pdfminer.layout import LAParams
from cStringIO import StringIO
def myparse(data):
fp = file(data, 'rb')
rsrcmgr = PDFResourceManager()
retstr = StringIO()
codec = 'utf-8'
laparams = LAParams()
device = TextConverter(rsrcmgr, retstr, codec=codec, laparams=laparams)
# Create a PDF interpreter object.
interpreter = PDFPageInterpreter(rsrcmgr, device)
# Process each page contained in the document.
for page in PDFPage.get_pages(fp):
interpreter.process_page(page)
#fp.close()
#device.close()
str = retstr.getvalue()
#retstr.close()
return str
t1 = myparse("part2.pdf")
text_file = open("part2.txt", "w")
text_file.write(t1)
text_file.close()
Also, this returns the entire structure of the table of contents:
# Open a PDF document.
fp = open('solar.pdf', 'rb')
parser = PDFParser(fp)
password = ""
document = PDFDocument(parser, password)
# Get the outlines of the document.
outlines = document.get_outlines()
for (level,title,dest,a,se) in outlines:
print (level, title, a)
Any idea how to go ahead from here? Any tools using python, R or bash would be easiest to use for me personally, but as long as it enables batch splitting based on the first outline level of the document, any solution would be great.
Thank you,
Matthias
I've found a straightforward solution for this using sejda-console:
from subprocess import call
import os
pdfname = "example.pdf"
outdir = "C:\\out\\%s" % pdfname
if not os.path.exists(outdir):
os.makedirs(outdir)
sejda = 'C:\\sejda\\bin\\sejda-console.bat'
call = sejda
call += ' splitbybookmarks'
call += ' --bookmarkLevel 1'
call += ' -f "%s"' % pdfname
call += ' -o "%s"' % outdir
print '\n', call
subprocess.call(call)
print "PDFs have been written to out-directory"
Abviously this requires the sejda programme: http://www.sejda.org/

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