Extract comments from a pdf file and dump them into a markdown file for pretty formatting.

export-pdf-comments.py

# adapted from http://stackoverflow.com/a/12502560/379300
# Output should be valid markdown, so it can be turned into a nice pdf with pandoc
import poppler
import sys
import urllib
import os

def main():
    input_filename = sys.argv[1]
    # http://blog.hartwork.org/?p=612
    document = poppler.document_new_from_file('file://%s' % \
               urllib.pathname2url(os.path.abspath(input_filename)), None)
    n_pages = document.get_n_pages()
    all_annots = 0
  
    pages = []
    comments = []
    for i in range(n_pages):
        page = document.get_page(i)
        annot_mappings = page.get_annot_mapping ()
        num_annots = len(annot_mappings)
        if num_annots > 0:
            pages.append(i)
            comments.append([])
            for annot_mapping in annot_mappings:
                if  annot_mapping.annot.get_annot_type().value_name != 'POPPLER_ANNOT_LINK':
                    if type(annot_mapping.annot.get_contents()) is str:
                        all_annots += 1
                        comments[-1].append(annot_mapping.annot.get_contents())

    for cl,p in zip(comments,pages):
        if len(cl) > 0:
            print "Page "+str(p+1)
            print "====="
            for c in cl:
                print '- '+c
                print

    if all_annots > 0:
        print str(all_annots) + " annotation(s) found"
    else:
        print "no annotations found"

if __name__ == "__main__":
    main()