1
2
3
4

from itertools import groupby
import doctest

...

1
2
3
4

def mk_index(seq):
    """Index a sequence
    >>> sorted(mk_index("abcba").items())
...

1
2
3

idiom_A = lambda x,y,z: (x and [y] or [z])[0]
idiom_B = lambda x,y,z: (z, y)[x]
idiom_C = lambda x,y,z: y if x else z # introduced in Python 2.5

1
2
3
4

#!/usr/bin/python2.5
def permute(li):
    """Generate all permutations of a sequence
...