using None as an index has the same effect as a missing index : Index « String « Python Tutorial






  1. Python Tutorial
  2. String
  3. Index
s = 'abcde'
for i in [None] + range(-1, -len(s), -1):
    print s[:i]








5.11.Index
5.11.1.String literals and other sequence literals may be indexed directly, without using a variable to refer to them
5.11.2.find the index of a substring
5.11.3.index with offset
5.11.4.using None as an index has the same effect as a missing index