add: function to split up text (or lists)

[GoogleCodeExporter]

added in transform.py
can be called recursive, see examples.

def chunk(sequence, size):
    ''' return generator for chunks 
        input: string, list, tuple.
        uses cases:
        print list(chunk([1,2,3,4,5,6,7,8,9,10],3))     #[[1, 2, 3], [4, 5, 6], [7, 8, 9], [10]]
        print list(chunk('a nice example string',5))    #['a nic', 'e exa', 'mple ', 'strin', 'g']
        print list(chunk(list(chunk('a nice example string',5)),2)) [['a nic', 'e exa'], ['mple ', 'strin'], ['g']]
        print list(chunk(list(chunk('',5)),2))          #[]
        print list(chunk(list(chunk(None,5)),2))        #[]
    '''

Original issue reported on code.google.com by hjebb...@gmail.com on 20 May 2015 at 2:58