之前得到了很多文章的pdf，现在需要把它们合到一个pdf文件中。
使用python库pypdf2可以实现这个功能。
首先要安装
pip install pypdf2
然后运行下面的示例 python mergePDF.py
mergePDF.py

# -*- coding:utf-8*-

import os
import os.path
from PyPDF2 import PdfFileReader, PdfFileWriter
import time
import glob


def getFileName(filepath):
    file_list = glob.glob("{}/*.pdf".format(filepath))
    # 默认按照字典序排序，也可以安装自定义的方式排序
    # file_list.sort()
    return file_list

###########合并同一个文件夹下所有PDF文件###############
def MergePDF(filepath, outfile):
    output = PdfFileWriter()
    outputPages = 0
    pdf_fileName = getFileName(filepath)
    for each_file in pdf_fileName:
        print("adding %s" % each_file)
        # 读取源pdf文件
        input = PdfFileReader(open(each_file, "rb"))

        # 如果pdf文件已经加密，必须首先解密才能使用pyPdf
        if input.isEncrypted == True:
            input.decrypt("map")

        # 获得源pdf文件中页面总数
        pageCount = input.getNumPages()
        outputPages += pageCount
        print("%s has %d pages" % (each_file, pageCount))

        # 分别将page添加到输出output中
        for iPage in range(pageCount):
            output.addPage(input.getPage(iPage))

        # 添加书签
        each_file = os.path.basename(each_file)
        output.addBookmark(
            title=each_file[:-3], pagenum=outputPages - pageCount)

    print("All Pages Number: " + str(outputPages))
    # 最后写pdf文件
    outputStream = open(os.path.join(filepath, outfile), "wb")
    output.write(outputStream)
    outputStream.close()
    print("finished")


if __name__ == '__main__':
    time1 = time.time()
    file_dir = '.' # 多个pdf所在目录
    out_file = u"test.pdf" # 合并后的pdf文件名
    MergePDF(file_dir, out_file)
    time2 = time.time()
    print(u'总共耗时： %.4f s' % (time2 - time1))

结果输出如下：
D:\Program Files\phantomjs-2.1.1-windows\bin>python mergePDF.py
adding 3.pdf
3.pdf has 1 pages
adding 4.pdf
4.pdf has 1 pages
adding baidu.pdf
baidu.pdf has 1 pages
adding fun.pdf
fun.pdf has 1 pages
adding fun1.pdf
fun1.pdf has 1 pages
adding fun10.pdf
fun10.pdf has 8 pages
adding fun2.pdf
fun2.pdf has 1 pages
adding fun3.pdf
fun3.pdf has 1 pages
adding fun4.pdf
fun4.pdf has 8 pages
adding fun5.pdf
fun5.pdf has 1 pages
adding fun6.pdf
fun6.pdf has 1 pages
adding fun7.pdf
fun7.pdf has 8 pages
adding fun8.pdf
fun8.pdf has 1 pages
adding fun9.pdf
fun9.pdf has 1 pages
adding sai.pdf
sai.pdf has 1 pages
All Pages Number: 36
finished
总共耗时： 0.4700 s

生成的pdf效果如下：