Marca de agua de Python PDF

Marca de agua de Python PDF

from PyPDF2 import PdfWriter,PdfReader
from reportlab.lib.units import cm
from reportlab.pdfgen import canvas
import reportlab.pdfbase.ttfonts
from reportlab.pdfbase import pdfmetrics
import os

basedir=os.path.dirname(os.path.abspath(__file__))


def create_watermark(content):
    """水印信息"""
    # 默认大小为21cm*29.7cm
    file_name = os.path.join(basedir,"../../media/mark.pdf")
    c = canvas.Canvas(file_name, pagesize=(30 * cm, 30 * cm))
    # 移动坐标原点(坐标系左下为(0,0))
    c.translate(10 * cm, 5 * cm)
    try:
        # 注册中文字体
        pdfmetrics.registerFont(reportlab.pdfbase.ttfonts.TTFont('yahei', '微软雅黑.ttf'))
        c.setFont('yahei',20)
    except:
        # 设置字体
        c.setFont("Helvetica", 30)
    # 指定描边的颜色
    c.setStrokeColorRGB(0, 1, 0)
    # 指定填充颜色
    c.setFillColorRGB(0, 0, 222,0.2)
    # 旋转45度,坐标系被旋转
    c.rotate(30)
    # 指定填充颜色
    # c.setFillColorRGB(0, 0, 0, 0.1)
    # 设置透明度,1为不透明
    c.setFillAlpha(0.1)
    # 画几个文本,注意坐标系旋转的影响
    for i in range(5):
        for j in range(10):
            a = 10 * (i - 1)
            b = 5 * (j - 2)
            c.drawString(a * cm, b * cm, content)
            c.setFillAlpha(0.1)
    # 关闭并保存pdf文件
    c.save()
    return file_name

def add_watermark(pdf_file_in, pdf_file_mark, pdf_file_out):
    """把水印添加到pdf中"""
    pdf_output = PdfWriter()
    input_stream = open(pdf_file_in, 'rb')
    pdf_input = PdfReader(input_stream, strict=False)

    # 获取PDF文件的页数
    pageNum = len(pdf_input.pages)

    # 读入水印pdf文件
    pdf_watermark = PdfReader(open(pdf_file_mark, 'rb'), strict=False)
    # 给每一页打水印
    for i in range(pageNum):
        page = pdf_input.pages[i]
        page.merge_page(pdf_watermark.pages[0])
        page.compress_content_streams()  # 压缩内容
        pdf_output.add_page(page)
    pdf_output.write(open(pdf_file_out, 'wb'))