User Name Password Register
DaniWeb IT Discussion Community
All
What is DaniWeb IT Discussion Community?
You're currently browsing the Python section within the Software Development category of DaniWeb, a massive community of 363,779 software developers, web developers, Internet marketers, and tech gurus who are all enthusiastic about making contacts, networking, and learning from each other. In fact, there are 4,502 IT professionals currently interacting right now! Registration is free, only takes a minute and lets you enjoy all of the interactive features of the site.
Please support our Python advertiser:
May 14th, 2008
Views: 762
Returns the power set of the elements of a given list (even if some of those elements are also lists).
python Syntax
  1. # From another DaniWeb snippet
  2. def int2bin(n, count=24):
  3. """returns the binary of integer n, using count number of digits"""
  4. return "".join([str((n >> y) & 1) for y in range(count-1, -1, -1)])
  5.  
  6. # PowerSet of a List
  7. def PowerSet(orignal_list):
  8. list_size = len(orignal_list)
  9. num_sets = 2**list_size
  10. powerset = []
  11. # Don't include empty set
  12. for i in range(num_sets)[1:]:
  13. subset = []
  14. binary_digits = list(int2bin(i,list_size))
  15. list_indices = range(list_size)
  16. for (bit,index) in zip(binary_digits,list_indices):
  17. if bit == '1':
  18. subset.append(orignal_list[index])
  19. powerset.append(subset)
  20. return powerset
  21.  
  22. if __name__ == "__main__":
  23. print PowerSet([1,2,3])
Post Comment

Only community members can submit or comment on code snippets. You must register or log in to contribute.

DaniWeb Marketplace (Sponsored Links)
All times are GMT -4. The time now is 10:36 am.
Forum system based on vBulletin Copyright ©2000 - 2008, Jelsoft Enterprises Ltd.
©2003 - 2008 DaniWeb® LLC