Fill PDF and merge with another PDF

[CoPython]

Good day,

I'm still new and I also realize that some codes could really be easier. I'm still trying out the python part and learning more about it.

Does anyone have an idea how I can merge 3 PDFs together but also fill PDF 1 by using a PDF form with input fields and field names?

The code below partially works on OSX but not on Windows due to an error message from PyPDF. On OSX it unfortunately does not fill in the forms. It seems that the export creates a PDF that is no longer fillable.

So what I want exactly:
A list of options. After selection, it merges the selected PDF files and in 1 PDF the fields are provided with the data from Excel

Part of the entire script:

    
# Database Inladen Python3
from tkinter import Tk
from fillpdf import fillpdfs
from tkinter.filedialog import askdirectory
from tkinter import *
import xlrd
import webbrowser
import tkinter as tk
import glob
from PyPDF2 import PdfFileMerger


def display_input():
        number_as_string1 = str(var1.get())
        var1PDF = number_as_string1.replace(str(1), "Database/InstallQ/1.pdf")
        var1PDF2 = var1PDF.replace(str(0), "")
        
        number_as_string2 = str(var2.get())
        var2PDF = number_as_string2.replace(str(1), "Database/InstallQ/2.pdf")
        var2PDF2 = var2PDF.replace(str(0), "")
        
        number_as_string3 = str(var3.get())
        var3PDF = number_as_string3.replace(str(1), "Database/InstallQ/3.pdf")
        var3PDF2 = var3PDF.replace("0", "")

        allepdf = [var1PDF2,var2PDF2,var3PDF2]

        list_with_empty_strings = list(allepdf)

        new_list = [x for x in list_with_empty_strings if x != '']

        print(new_list)

        # Input pad
        path2 = askdirectory(title='Selecteer de folder met berekeningen') 
        path3 = path2+'/*.xls'        

        # Output Pad
        doellocatie2 = askdirectory(title='Selecteer InstallQ Locatie') 
        output_file = doellocatie2+"/InstallQ.pdf"

        merger = PdfFileMerger()

        for pdf in new_list:
            merger.append(pdf)

        merger.write(output_file)
        merger.close()
    
        files2 = glob.glob(path3)
    
        i = 0
        while i < len(files2):
        
            # Excel File openen
            excel_workbook = xlrd.open_workbook(files2[i])
            excel_worksheet_2021 = excel_workbook.sheet_by_name('CSV Export')


            # Selecteer Data uit XLS
            ID01ex = excel_worksheet_2021.cell_value(1, 1)  # Projectnummer
            ID02ex = excel_worksheet_2021.cell_value(2, 1)  # Kavelnummer
            ID04ex = excel_worksheet_2021.cell_value(4, 1)  # Merk en type Ventilator
            ID05ex = excel_worksheet_2021.cell_value(5, 1)  # Serienr:
            ID06ex = excel_worksheet_2021.cell_value(6, 1)  # Inregeling uitgevoerd door:
            ID07ex = excel_worksheet_2021.cell_value(7, 1)  # Datum
            ID08ex = excel_worksheet_2021.cell_value(8, 1)  # Woonkamer 1 Inblaas
            ID09ex = excel_worksheet_2021.cell_value(9, 1)  # Woonkamer 2 Inblaas
            ID20ex = excel_worksheet_2021.cell_value(10, 1) # TOTAAL INBLAAS

            # Lege Regels aanvullen ter voorkoming van foutmelding
            try:
                ID01 = int(ID01ex) # Projectnummer
            except:
                ID01 = int("")

            try:
                ID02 = str(ID02ex) # Kavelnummer
            except:
                ID02 = str("")
    
            try:
                ID04 = str(ID04ex) # Merk en type Ventilator
            except:
                ID04 = str("")
    
            try:
                ID05 = int(ID05ex) # Serienr:
            except:
                ID05 = int("")
    
            try:
                ID06 = str(ID06ex) # Inregeling uitgevoerd door:
            except:
                ID06 = str("")
    
            try:
                ID07 = str(ID07ex) # Datum
            except:
                ID07 = str("")
    
            try:
                ID08 = int(ID08ex) # Woonkamer 1 Inblaas
            except:
                ID08 = int("")

            try:
                ID09 = int(ID09ex) # Woonkamer 2 Inblaas
            except:
                ID09 = int("")

            try:
                ID20 = int(ID20ex) # TOTAAL INBLAAS
            except:
                ID20 = int("")
  
            # Open PDF Files  
            fillpdfs.get_form_fields(output_file)
            print (output_file)

            # Data Toevoegen aan PDF
            data_dict = {
            '5 Merk en type Ventilator': ID04,
            '6 serienummer Ventilator': ID05,
            '7 Inregeling Uitgevoerd door': ID06,
            '8 Datum inregeling': ID07,
            'Tekstveld198': ID08,
            'Tekstveld199': ID09,
            'totaal 1': ID20,
            }

            # Savenaam aanmaken
            ID01naam = str(ID01) # Projectnummer
            ID02naam = str(ID02) # Kavelnummer
            Savenaam = doellocatie2+"/"+ID01naam+"_bnr"+ID02naam+".pdf"
            Savenaam2 = Savenaam.replace( ".0.pdf" , ".pdf" )
            
            print (Savenaam2)


            # PDF Opslaan
            fillpdfs.write_fillable_pdf(output_file, Savenaam2, data_dict)
        
            i = i + 1


# Lege Radiobuttons
    var1 = IntVar()
    var2 = IntVar()
    var3 = IntVar()
    
    # Checkboxen
    t1 = Checkbutton(toplevel, text="PDF 1", variable=var1, onvalue=1, offvalue=0)
    t1.grid(row=0, column=0, sticky=NW, pady=50, padx=10)
    t2 = Checkbutton(toplevel, text="PDF 2", variable=var2, onvalue=1, offvalue=0)
    t2.grid(row=0, column=0, sticky=NW, pady=80, padx=10)
    t3 = Checkbutton(toplevel, text="PDF 3", variable=var3, onvalue=1, offvalue=0)
    t3.grid(row=0, column=0, sticky=NW, pady=110, padx=10)
    
    t9 = Label(toplevel, text='Mail', cursor="hand2", relief='raised', foreground='Black', image=dwnd2, borderwidth = 0, width=85,
    height=28, bd='0', highlightthickness = 0)
    t9.grid(row=0, column=0, sticky=SW, pady=140, padx=10)
    t9.bind("<Button-1>", lambda e:display_input())