Extract Pages from PDF based on search in python

Question

Everything is working fine except timing. it takes lot time for my file containing 1000 pages and having 100 pages of interest.

import re
from PyPDF2 import PdfFileReader, PdfFileWriter
import glob, os
# find pages
def findText(f, slist):
 file = open(f, 'rb')
 pdfDoc = PdfFileReader(file)
 pages = []
 for i in range(pdfDoc.getNumPages()):
 content = pdfDoc.getPage(i).extractText().lower()
 for s in slist:
 if re.search(s.lower(), content) is not None:
 if i not in pages:
 pages.append(i)
 return pages
#extract pages
def extractPage(f, fOut, pages):
 file = open(f, 'rb')
 output = PdfFileWriter()
 pdfOne = PdfFileReader(file)
 for i in pages:
 output.addPage(pdfOne.getPage(i))
 outputStream = open(fOut, "wb")
 output.write(outputStream)
 outputStream.close()
 return
os.chdir(r"path\to\mydir")
for pdfFile in glob.glob("*.pdf"):
 print(pdfFile)
 outPdfFile = pdfFile.replace(".pdf","_searched_extracted.pdf")
 stringList = ["string1", "string2"]
 extractPage(pdfFile, outPdfFile, findText(pdfFile, stringList))

Updated code after suggestions is at:

https://gist.github.com/pra007/099f10b07be5b7126a36438c67ad7a1f

• Quentin Pradet: We don't really care about the overall time but more about the specifics. Instead of python file.py, use python -m cProfile -s cumtime file.py and post the functions that took the most time.
• Rahul Patel: is my modified code OK?
• 200_success: I have rolled back the question to Rev 1. Please see What to do when someone answers .
• Rahul Patel: Thanks. I will keep in mind next time not to change the question.

Answer 1

You could try profiling but the code is simple enough that I think you're spending most of the time in PyPDF2 code. Two options:

• You can preprocess your PDF files to store their text somewhere, which will make the search phase much faster, especially if you run multiples queries on the same PDF files
• You can try another parser such as a Python 3 version of PDFMiner, or even a parser written in a faster language

• Rahul Patel: Thanks. I thought pdfminer is dead. let me test pdfminer3k
• Quentin Pradet: @Rahul Preprocessing sounds better. It's not an option for you?

Answer 2

One thing that might help a lot is to compile your regexs just once. Instead of

def findText(f, slist):
 file = open(f, 'rb')
 pdfDoc = PdfFileReader(file)
 pages = []
 for i in range(pdfDoc.getNumPages()):
 content = pdfDoc.getPage(i).extractText().lower()
 for s in slist:
 if re.search(s.lower(), content) is not None:
 if i not in pages:
 pages.append(i)
 return pages

try:

def findText(f, slist):
 file = open(f, 'rb')
 pdfDoc = PdfFileReader(file)
 pages = []
 searches = [ re.compile(s.lower()) for s in slist ]
 for i in range(pdfDoc.getNumPages()):
 content = pdfDoc.getPage(i).extractText().lower()
 for s in searches:
 if s.search(content) is not None:
 if i not in pages:
 pages.append(i)
 return pages

Also, you can short-circuit out a lot faster than you're doing:

def findText(f, slist):
 file = open(f, 'rb')
 pdfDoc = PdfFileReader(file)
 pages = []
 searches = [ re.compile(s.lower()) for s in slist ]
 for i in range(pdfDoc.getNumPages()):
 content = pdfDoc.getPage(i).extractText().lower()
 for s in searches:
 if s.search(content) is not None:
 pages.append(i)
 break
 return pages