HYTOS

import os

pngPath = "E:\Projects\CPChem\drawings"

pdfPath = os.path.join("E:\Projects\CPChem", "aa")

pngList = os.listdir(pngPath)

pdfList = os.listdir(pdfPath)

for index in range(len(pngList)):

    pngList[index] = pngList[index].replace('_Page1.png', '')

for index in range(len(pdfList)):

    pdfList[index] = pdfList[index].replace('.pdf', '')

for index in range(len(pngList) - 1, -1, -1):

    if pngList[index] in pdfList:

        pngList.pop(index)

for png in pngList:

    print(png)

print('=======')

pngList = os.listdir(pngPath)

pdfList = os.listdir(pdfPath)

for index in range(len(pngList)):

    pngList[index] = pngList[index].replace('_Page1.png', '')

for index in range(len(pdfList)):

    pdfList[index] = pdfList[index].replace('.pdf', '')

for index in range(len(pdfList) - 1, -1, -1):

    if pdfList[index] in pngList:

        pdfList.pop(index)

for png in pdfList:

    print(png)