最近做了一个小功能，将一个页面上面的所有图片下载下来生成一个PDF文件。发现了一个非常好用的库reportlab, pyPdf。只需要几行代码就能实现功能，如果没有安装可以通过pip安装：
pip install reportlab -i https://pypi.douban.com/simple
pip install pyPdf -i https://pypi.douban.com/simple
注: -i表示使用豆瓣的镜像服务
操作过程
下面记录下我的处理的过程：
（1）如果只是简单的需要将图片进行拼接成PDF可以直接使用如下的方式：
from reportlab.lib.pagesizes import A4, portrait, landscape
from reportlab.pdfgen import canvas
def convert_images_to_pdf(img_path, pdf_path):
pages = 0
(w, h) = portrait(A4)
c = canvas.Canvas(pdf_path, pagesize = portrait(A4))
l = os.listdir(img_path)
l.sort(key= lambda x:int(x[:-4]))
for i in l:
f = img_path + os.sep + str(i)
c.drawImage(f, 0, 0, w, h)
c.showPage()
pages = pages + 1
c.save()
（2）如果需要根据不同的尺寸的图片设置横屏还是竖屏模式，可以考虑使用如下方式实现：
import os, shutil
from PIL import Image
from reportlab.lib.pagesizes import A4, portrait, landscape
from reportlab.pdfgen import canvas
from pyPdf import PdfFileWriter, PdfFileReader
def convert_image_to_pdf(img_path, pdf_path):
img = Image.open(img_path)
(w0, h0) = img.size
if w0 > h0:
(w, h) = landscape(A4)
c = canvas.Canvas(pdf_path, pagesize = landscape(A4))
c.drawImage(img_path, 0, 0, w, h)
c.showPage()
c.save()
else:
(w, h) = portrait(A4)
c = canvas.Canvas(pdf_path, pagesize = portrait(A4))
c.drawImage(img_path, 0, 0, w, h)
c.showPage()
c.save()
def convert_images_to_pdf(img_path, pdf_path):
pages = 0
tmp_path = '.' + os.sep + 'temp'
if not os.path.exists(tmp_path):
os.mkdir(tmp_path)
list = os.listdir(img_path)
list.sort(key=lambda x:int(x[:-4]))
output = PdfFileWriter()
for item in list:
img = img_path + os.sep + str(item)
pdf = tmp_path + os.sep + str(pages + 1) + ".pdf"
convert_image_to_pdf(img, pdf)
input = PdfFileReader(file(pdf, "rb"))
pageCount = input.getNumPages()
pages = pages + 1
for iPage in range(0, pageCount):
output.addPage(input.getPage(iPage))
outputStream = file(pdf_path, "wb")
output.write(outputStream)
outputStream.close()
shutil.rmtree(tmp_path)