import img2pdf

with open("gentleman.pdf","wb") as f:

f.write(img2pdf.convert('gentleman.png'))

with open("sample.pdf","wb") as f:

f.write(img2pdf.convert('sample.jpg'))

with open("output1.pdf","wb") as f:

f.write(img2pdf.convert("gentleman.png", "sample.jpg"))

with open("output2.pdf","wb") as f:

f.write(img2pdf.convert(["gentleman.png", "sample.jpg"]))

a4inpt = (img2pdf.mm_to_pt(210),img2pdf.mm_to_pt(297))

layout_fun = img2pdf.get_layout_fun(a4inpt)

with open("paper_size.pdf","wb") as f:

f.write(img2pdf.convert('sample.jpg', layout_fun=layout_fun))

You can go through the tutorial https://www.roytuts.com/convert-image-to-pdf-using-python/