Splits a sequence and returns a generator having split subsequences - See doc string for further info.

sequence_split.py

from math import ceil

def split(input_list,num_fractions=None,subset_length=None):
   '''                                                                                                                             
   Given a list/tuple split original list based on either one of two parameters given but NOT both,                                 

   Returns generator                                                                                                               
   num_fractions : Number of subsets original list has to be divided into, of same size to the extent possible.
                   It's possible that number of fractions returned is less than requested (num_fractions value)
                   In case, when you want to split a 6-member list into 4 subsets.
                   output in that case will be 3 subsets having 2 elements each.
                   Think about it, makes sense.
   subset_length : Split on every subset_length elements until the list is exhausted.
                   In case subset_length is not a proper divisor of length(input_list),
                   all but the last subset will have the same number of elements, 
                   last subset will have the remaining elems - length(input_list) % subset_length

   Example usage: Split a 8-element list into 4 subsets.
                  >> list(list_split.split(range(8),num_fractions=4))
                  :: [[0, 1], [2, 3], [4, 5], [6, 7]]
                 
                  Split a 8-element list on every 3rd element
                  >>list(list_split.split(range(8),subset_length=3))
                  :: [[0, 1, 2], [3, 4, 5], [6, 7]]
                                                                        
   '''
   if not input_list:
       yield input_list 
   elif not bool(num_fractions and num_fractions >=1 ) ^ \
          bool(subset_length and subset_length>= 1):  #validates params to be > 1
       raise Exception("Only one of the params : num_fractions,subset_length (x: x>=1) to be provided")
   else:
       if num_fractions >= 1: #derive subset_length from num_fractions in case it's not present
           subset_length = int( ceil( len(input_list) / float(num_fractions) ) )

       for start in xrange(0,len(input_list),subset_length):
           yield input_list[start:start+subset_length]