Update hocr-pdf

- Use base64.b64decode instead of base64.decodestring;
fix #145
- Add warning when no JPG images are found in directory;
fix #123
- Improve error handling; fix #35

hocr-pdf

@@ -50,11 +50,15 @@ class StdoutWrapper:
 
 def export_pdf(playground, default_dpi, savefile=False):
     """Create a searchable PDF from a pile of HOCR + JPEG"""
+    images = sorted(glob.glob(os.path.join(playground, '*.jpg')))
+    if len(images) == 0:
+        print("WARNING: No JPG images found in the folder", playground,
+              "\nScript cannot proceed without them and will terminate now.\n")
+        sys.exit(0)
     load_invisible_font()
     pdf = Canvas(savefile if savefile else StdoutWrapper(), pageCompression=1)
     pdf.setCreator('hocr-tools')
     pdf.setTitle(os.path.basename(playground))
-    images = sorted(glob.glob(os.path.join(playground, '*.jpg')))
     dpi = default_dpi
     for image in images:
         im = Image.open(image)
@@ -142,7 +146,7 @@ pylRc2Zn+XDQWZIL8iO5KC9S+1RekOex1uOyZGR/w/Hf1lhzqVfFsxE39B/ws7Rm3N3nDrhPuMfc
 w3R/aE28KsfY2J+RPNp+j+KaOoCey4h+Dd48b9O5G0v2K7j0AM6s+5WQ/E0wVoK+pA6/3bup7bJf
 CMGjwvxTsr74/f/F95m3TH9x8o0/TU//N+7/D/ScVcA=
 """.encode('latin1')
-    uncompressed = bytearray(zlib.decompress(base64.decodestring(font)))
+    uncompressed = bytearray(zlib.decompress(base64.b64decode(font)))
     ttf = io.BytesIO(uncompressed)
     setattr(ttf, "name", "(invisible.ttf)")
     pdfmetrics.registerFont(TTFont('invisible', ttf))
@@ -162,4 +166,6 @@ if __name__ == "__main__":
         help="Save to this file instead of outputting to stdout"
     )
     args = parser.parse_args()
+    if not os.path.isdir(args.imgdir):
+        sys.exit("ERROR: Given path '" + args.imgdir + "' is not a directory")
     export_pdf(args.imgdir, 300, args.savefile)