1 2 3 4 5 6 7 | def subs(xs, sub_len): '''Get all sublists/substrings from xs of the given sub-length.''' for i in range(len(xs) - sub_len + 1): #Get all indexes of the substrings that are at least sub_len long. yield xs[i:i+sub_len]for x in subs('abcd', 2): print(x) |
ab bc cd
1 2 3 4 5 6 7 8 9 10 11 | def combinations(xs, comb_size): '''Get all combinations of the given combination size.''' if comb_size == 0: yield xs[:0] #Empty list/string else: for i in range(len(xs) - comb_size + 1): for ys in combinations(xs[i+1:], comb_size-1): #For every item, combine it with every item that comes after it. yield xs[i] + ysfor x in combinations('abcd', 2): print(x) |
ab ac ad bc bd cd
1 2 3 4 5 6 7 8 9 10 11 | def perms(xs): '''Get all permutations.''' if len(xs) == 1: yield xs else: for i in range(len(xs)): for ys in perms(xs[:i] + xs[i+1:]): #For every item, combine it with every item except itself. yield xs[i] + ysfor x in perms('abc'): print(x) |
abc acb bac bca cab cba
1 2 3 4 5 6 7 8 | def permutations(xs, perm_size): '''Get all permutations of the given permutation size.''' for cs in combinations(xs, perm_size): for p in perms(cs): #Get all the permutations of all the combinations. yield pfor x in permutations('abcd', 2): print(x) |
ab ba ac ca ad da bc cb bd db cd dc
1 2 3 4 5 6 7 8 9 10 11 | def seqs(xs, seq_len): '''Get all sequences of a given length.''' if seq_len == 0: yield xs[:0] #Empty list/string else: for i in range(len(xs)): for ys in seqs(xs, seq_len-1): #For every item, combine it with every item including itself. yield xs[i] + ysfor x in seqs('abc', 2): print(x) |
aa ab ac ba bb bc ca cb cc
