from PyPDF2 import PdfReader, PdfWriter, Transformation

# Read the input
reader = PdfReader("input.pdf")
page = reader.pages[0]

# Scale
op = Transformation().scale(sx=0.7, sy=0.7)
page.add_transformation(op)

# Write the result to a file
writer = PdfWriter()
writer.add_page(page)
writer.write("output.pdf")