Python Invoice Generator: Automated PDF Billing With Payment Reminders Late invoices cause late payments. I automated my entire billing system with 150 lines of Python. PDF Invoice Generator from reportlab.lib import colors from reportlab.lib.pagesizes import letter from reportlab.platypus import SimpleDocTemplate , Table , TableStyle , Paragraph from reportlab.lib.styles import getSampleStyleSheet from datetime import datetime , timedelta def create_invoice ( client_name , client_email , services , invoice_num ): filename = f " invoice_ { invoice_num } .pdf " doc = SimpleDocTemplate ( filename , pagesize = letter ) styles = getSampleStyleSheet () elements = [] elements . append ( Paragraph ( f " INVOICE # { invoice_num } " , styles [ ' Title ' ])) elements . append ( Paragraph ( f " Date: { datetime . now (). strftime ( ' %B %d, %Y ' ) } " , styles [ ' Normal ' ])) elements . append ( Paragraph ( f " Due: { ( datetime . now () + timedelta ( days = 30 )).…