remover.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# PyPDF2 -  a Python library that allows reading, writing, and manipulating PDF files
from PyPDF2 import PdfReader, PdfWriter
from PyPDF2.generic import NumberObject, TextStringObject, NameObject

from PyPDF2.generic import ContentStream

# tkinter - used for building the GUI (Graphical User Interface) application
from tkinter import Tk, Label, Button, StringVar
from tkinter.filedialog import askopenfilename, asksaveasfilename, askdirectory
from tkinter.constants import N,S,W,E, LEFT, TOP, RIGHT, BOTTOM
import sys, os
import tkinter.font as font

# reportlab - a library for generating PDFs programmatically
from reportlab.pdfgen import canvas

def resource_path(relative_path):
    if hasattr(sys, '_MEIPASS'):
        return os.path.join(sys._MEIPASS, relative_path)
    return os.path.join(os.path.abspath("."), relative_path)


class PdfEnhancedFileWriter(PdfWriter):

    colors_operands = {
        'rgb': {
            'black': [NumberObject(0), NumberObject(0), NumberObject(0)],
            'white': [NumberObject(1), NumberObject(1), NumberObject(1)],
        },
        'cmyk': {
            'black': [NumberObject(0), NumberObject(0), NumberObject(0), NumberObject(1)],
            'white': [NumberObject(0), NumberObject(0), NumberObject(0), NumberObject(0)],
        },
        'grayscale': {
            'black': [NumberObject(0)],
            'white': [NumberObject(1)],
        }
    }

    def _getOperatorType(self, operator):
        operator_types = {
            (b"Tj"): "text",
            (b"'"): "text",
            (b'"'): "text",
            (b"TJ"): "text",
            (b"rg"): "rgb",  # color
            (b"RG"): "rgb",  # color
            (b"k"): "cmyk",  # color
            (b"K"): "cmyk",  # color
            (b"g"): "grayscale",  # color
            (b"G"): "grayscale",  # color
            (b"re"): "rectangle",
            (b"l"): "line",  # line
            (b"m"): "line",  # start line
            (b"S"): "line",  # stroke(paint) line
        }

        if operator in operator_types:
            return operator_types[operator]

        return None

    # get the operation type that the color affects on
    def _getColorTargetOperationType(self, color_index, operations):

        for i in range(color_index + 1, len(operations)):
            operator = operations[i][1]

            operator_type = self._getOperatorType(operator)

            if operator_type == 'text' or operator_type == 'rectangle' or operator_type == 'line':
                return operator_type

        return False


    def getMinimumRectangleWidth(self, fontSize, minimumNumberOfLetters = 1.5):
        return fontSize * minimumNumberOfLetters

    def removeWordStyle(self, ignoreByteStringObject=False):
        """
        Removes imported styles from Word - Path Constructors rectangles - from this output.

        :param bool ignoreByteStringObject: optional parameter
            to ignore ByteString Objects.
        """

        pages = self.get_object(self._pages)['/Kids']
        for page in pages:
            pageRef = self.get_object(page)
            content = pageRef["/Contents"].get_object()

            if not isinstance(content, ContentStream):
                content = ContentStream(content, pageRef)

            _operations    = []
            last_font_size = 0

            for operator_index, (operands, operator) in enumerate(content.operations):

                if operator == (b'Tf') and operands[0][:2] == '/F':
                    last_font_size = operands[1].as_numeric()

                if operator == (b'Tj'):
                    text = operands[0]
                    if ignoreByteStringObject:
                        if not isinstance(text, TextStringObject):
                            operands[0] = TextStringObject()
                elif operator == (b"'"):
                    text = operands[0]
                    if ignoreByteStringObject:
                        if not isinstance(text, TextStringObject):
                            operands[0] = TextStringObject()
                elif operator == (b'"'):
                    text = operands[2]
                    if ignoreByteStringObject:
                        if not isinstance(text, TextStringObject):
                            operands[2] = TextStringObject()
                elif operator == (b"TJ"):
                    for i in range(len(operands[0])):
                        if ignoreByteStringObject:
                            if not isinstance(operands[0][i], TextStringObject):
                                operands[0][i] = TextStringObject()


                operator_type = self._getOperatorType(operator)

                # we are ignoring all grayscale colors
                # tests showed that black underlines,borders and tables are defined by grayscale and aren't using rgb/cmyk colors
                if operator_type == 'rgb' or operator_type == 'cmyk':

                    color_target_operation_type = self._getColorTargetOperationType(operator_index, content.operations)

                    new_color = None

                    # we are coloring all text in black and all rectangles in white
                    # removing all colors paints rectangles in black which gives us unwanted results
                    if color_target_operation_type == 'text':
                        new_color = 'black'
                    elif color_target_operation_type == 'rectangle':
                        new_color = 'white'

                    if new_color:
                        operands = self.colors_operands[operator_type][new_color]


                # remove styled rectangles (highlights, lines, etc.)
                # the 're' operator is a Path Construction operator, creates a rectangle()
                # presumably, that's the way word embedding all of it's graphics into a PDF when creating one
                if operator == (b're'):

                    rectangle_width  = operands[-2].as_numeric()
                    rectangle_height = operands[-1].as_numeric()

                    minWidth  = self.getMinimumRectangleWidth(last_font_size, 1) # (length of X letters at the current size)
                    maxHeight = last_font_size + 6 # range to catch really big highlights
                    minHeight = 1.5 # so that thin lines will not be removed

                    # remove only style that:
                        # it's width are bigger than the minimum
                        # it's height is smaller than maximum and larger than minimum
                    if rectangle_width > minWidth and rectangle_height > minHeight and rectangle_height <= maxHeight:
                        continue

                _operations.append((operands, operator))

            content.operations = _operations
            pageRef.__setitem__(NameObject('/Contents'), content)

root = Tk()
root.title('Answers Remover 2.0')
#root.iconbitmap( resource_path('./icon.ico'))
pdf_list = []
filePaths = []

filename1 = StringVar()
src_pdf   = StringVar()


def createMultiPage(file_path):
    c = canvas.Canvas(file_path)

    for i in range(c.getPageNumber()):
        page_num = c.getPageNumber()
        text = "This is page %s"
        c.drawString(50, 50, text)
        # c.showPage()
    c.save()


def load_pdf(filename):
    f = open(filename,'rb')
    return PdfReader(f)

def load1():
    f = askopenfilename(multiple=True, filetypes=(('PDF File', '*.pdf'), ('All Files', '*.*')))
    var = root.tk.splitlist(f)
    for file in var:
        filePaths.append(file)
        message_var = str(len(pdf_list) + 1) + " file(s) loaded"
        filename1.set(message_var)
        # filename1.set(file.split('/')[-1])
        src_pdf = file
        # print(file)
        # print(src_pdf)
        pdf1 = load_pdf(file)
        pdf_list.append(pdf1)
        # pdf_list.append(file)
        print("Loaded " + file)

    # prints the loaded list
    #print(pdf_list)

def add_to_writer(pdfsrc, writer):
    [writer.add_page(pdfsrc.pages[i]) for i in range(len(pdfsrc.pages))]
    writer.removeWordStyle()

def remove_images():
    writer          = PdfEnhancedFileWriter()
    # output_filename = asksaveasfilename(filetypes = (('PDF File', '*.pdf'), ('All Files','*.*')))
    output_saving_dir = askdirectory(title="Choose output folder...")
    i = 0
    for file in pdf_list:
        head, tail = os.path.split(filePaths[i])
        print(tail)
        file_path = os.path.join(output_saving_dir, "SCRAPED_" + tail)
        outputfile = open(file_path, 'wb')
        add_to_writer(file, writer)
        writer.write(outputfile)
        outputfile.close()
        i = i + 1
        print(str(i) + " file(s) done")

    print("Job is done")
    root.quit()


##Label(root, text="Rectangles remover").grid(row=0, column=2, sticky=E)
Button(root, text="Choose one or more PDFs", command=load1, height=5, width=20).grid(row=1, column=0)
Button(root, text="Choose one or more PDFs", command=load1, font='Helvetica 12 bold', fg="green", height=4,
       width=20).grid(row=1, column=0)
Label(root, textvariable=filename1, width=20).grid(row=1, column=1, sticky=(N,S,E,W))
#photo= PhotoImage(file=resource_path('./button_pic.png'))

#Button(root, text="Remove answers",image=photo, command=remove_images, width=100, height=120).grid(row=1, column=2,sticky=E)
Button(root, text="Remove answers", command=remove_images, font='Helvetica 12 bold', fg="red", height=4).grid(row=1, column=2, sticky=E)

#Label(root, text="Remove Answers^^").grid(row=2, column=2, sticky=E)
#Label(root, text="Good Luck!").grid(row=2, column=0, sticky=W)

Label(root, text='''שימו לב,\n
האפליקציה מסירה אובייקטים מעוצבים שיובאו מוורד,\n
ולכן יש סיכוי שתסיר גם טבלאות ואלמנטים עיצוביים אחרים, אם קיימים.\n
הדף לא נפתח כראוי בתוכנות מסויימות של אדובי,\n
הפתרון הפשוט לכך הוא לחצן ימני על הקובץ שנוצר,\n
לחצן ימני > פתח באמצעות > כרום, פיירפוקס, או כל תוכנה אחרת שיודעת להציג פדף.\n
\n
וזיכרו: הפתרון הטוב ביותר יהיה לשלוח מייל חביב למתרגל האחראי לאחר המבחן\nולבקש ממנו להעלות גם גרסה ללא הפתרונות למען הסמסטרים הבאים.\n
\n
בהצלחה!\n''', font='Helvetica 7', justify=RIGHT).grid(row=3, columnspan=3, sticky=E)


for child in root.winfo_children():
    child.grid_configure(padx=10, pady=10)

root.mainloop()