from PyPDF2 import PdfFileWriter, PdfFileReader
import io
from reportlab.pdfgen import canvas
from reportlab.lib.pagesizes import A4
from reportlab.lib.units import mm
from reportlab.lib.styles import ParagraphStyle
from reportlab.platypus import Paragraph

my_Style=ParagraphStyle('My Para style',
fontName='Times-Roman',
#backColor='#F1F1F1',
fontSize=8,
#borderColor='#FFFF00',
#borderWidth=1,
#borderPadding=(5,5,5),
#leading=5,
alignment=1
)

packet = io.BytesIO()
def coord(x, y, height, unit=1):
    x, y = x * unit, height -  y * unit
    return x, y
c = canvas.Canvas(packet, pagesize=A4)
width, height = A4


p1=Paragraph('''<b>blablalblaflasldflasd śćććśćśćśćśćśćśćś</b>''',my_Style)
p1.wrapOn(c, (*coord(190, 25, height, mm)))
p1.drawOn(c, (*coord(10, 172, height, mm)))
c.showPage()
c.save()

#move to the beginning of the StringIO buffer
packet.seek(0)

# create a new PDF with Reportlab
new_pdf = PdfFileReader(packet)
# read your existing PDF
existing_pdf = PdfFileReader(open("original.pdf", "rb"))
output = PdfFileWriter()
# add the "watermark" (which is the new pdf) on the existing page
page = existing_pdf.getPage(0)
page.mergePage(new_pdf.getPage(0))
output.addPage(page)
# finally, write "output" to a real file
outputStream = open("destination30.pdf", "wb")
output.write(outputStream)
outputStream.close()