--- /dev/null
+import os
+import re
+
+
+filenames = os.listdir('.')
+
+file_tuples = []
+
+re_file = re.compile(r'^(\d\d)_(.*)$')
+
+for filename in filenames:
+ m = re_file.match(filename)
+
+ if m:
+ i = int(m.groups()[0])
+
+ t = i, filename
+
+ file_tuples.append(t)
+
+file_tuples = sorted(file_tuples, key=lambda t: t[0])
+
+for i, t in enumerate(file_tuples):
+ old_filename = file_tuples[i][1]
+
+ m = re_file.match(old_filename)
+
+ file_index = int(m.groups()[0])
+ filepart = m.groups()[1]
+
+ expected_index = i + 1
+
+ if file_index != expected_index:
+ new_filename = '%02d_%s' % (expected_index, filepart)
+
+ print 'rename %s to %s' % (old_filename, new_filename)
+
+ os.rename(old_filename, new_filename)