Python to flatten PDFs

Question

I found the following code that works fine on a PDF file in the same directory as the python file.

from spire.pdf.common import *
from spire.pdf import *

# Specify the input and output PDF file paths
inputFile = "2021-03-12 AJI-1 signed CR.pdf"
outputFile = "2021-03-12 AJI-1 signed CR.pdf"

# Create an object of the PdfDocument class
doc = PdfDocument()
# Load the PDF file
doc.LoadFromFile(inputFile)

# Flatten the form fields in the file
doc.Form.IsFlatten = True

# Save the resulting file
doc.SaveToFile(outputFile)
doc.Close()

However, I am trying to flatten all PDFs in sub folder So I amended the code as follows:

from spire.pdf.common import *
from spire.pdf import *
import os
import ctypes  # An included library with Python install.   

mydir =  "C:/New folder (5)/testPDFs/"
#mydir =  "C:/New folder (5)/testPDFs/*.pdf"
dir_list = os.listdir(mydir)
print(dir_list)
# Create an object of the PdfDocument class

for file in dir_list:
    ctypes.windll.user32.MessageBoxW(0, file, "Your title", 1)
    inputFile = file
    outputFile = file
    doc = PdfDocument()
    # Load the PDF file
    #doc.LoadFromFile(file)
    doc.LoadFromFile(mydir + file)
    print(mydir + file)
    doc.visable=True
    # Flatten the form fields in the file
    doc.Form.IsFlatten = True

    # Save the resulting file
    doc.SaveToFile(outputFile)
    doc.Close()

When I run this code I get the following error:

Traceback (most recent call last):
  File "C:\New folder (5)\flattenGroupTest.py", line 23, in <module>
    doc.Form.IsFlatten = True
AttributeError: 'NoneType' object has no attribute 'IsFlatten'

Why will it only work on a file in the current folder, and will it only work on one file?

Answer 1

You need to create and set the doc object fields and functions before running the for loop. Here is the adjusted code:

    from spire.pdf.common import *
    from spire.pdf import *
    import os
    import ctypes  # An included library with Python install.  
    mydir =  "C:/New folder (5)/testPDFs/"
    #mydir =  "C:/New folder (5)/testPDFs/*.pdf"
    dir_list = os.listdir(mydir)
    print(dir_list)

    # create and set fields and methods of doc object here
    doc = PdfDocument()
    doc.visable=True
    doc.Form.IsFlatten = True

    for file in dir_list:
        ctypes.windll.user32.MessageBoxW(0, file, "Your title", 1)
        inputFile = file
        outputFile = file
        doc.LoadFromFile(mydir + file)
        print(mydir + file)       
        Save the resulting file
        doc.SaveToFile(outputFile)
    doc.Close()

I hope you find this helpful.

Answer 2

After multiple tries this one seemed to work best for me

import os
from fillpdf import fillpdfs
#fillpdfs.flatten_pdf('filled.pdf', 'newflat.pdf')

mydir =  "C:/New folder (5)/testPDFs/"
topDir=  "C:/New folder (5)/newfolder/"
dir_list = os.listdir(mydir)
for file in dir_list:
    print(file)
    fillpdfs.flatten_pdf(mydir + file, topDir+ file)