python字典序问题实例

 import string all_letter = string.ascii_lowercase def gen_dict(): result = {} list_num_one = [ a_letter for a_letter in all_letter ] list_num_two = [ i + j for i in all_letter for j in all_letter[all_letter.find(i)+1:]] list_num_three = [ i + j + k for i in all_letter for j in all_letter[all_letter.find(i)+1:] for k in all_letter[all_letter.find(j)+1:]] list_num_four = [ i + j + k + l for i in all_letter for j in all_letter[all_letter.find(i)+1:] for k in all_letter[all_letter.find(j)+1:] for l in all_letter[all_letter.find(k)+1:]] list_num_five = [ i + j + k + l + m for i in all_letter for j in all_letter[all_letter.find(i)+1:] for k in all_letter[all_letter.find(j)+1:] for l in all_letter[all_letter.find(k)+1:] for m in all_letter[all_letter.find(l)+1:]] list_num_six = [ i + j + k + l + m + n  for i in all_letter for j in all_letter[all_letter.find(i)+1:] for k in all_letter[all_letter.find(j)+1:] for l in all_letter[all_letter.find(k)+1:] for m in all_letter[all_letter.find(l)+1:] for n in all_letter[all_letter.find(m)+1:] ] for key,value in enumerate(list_num_one + list_num_two + list_num_three + list_num_four + list_num_five + list_num_six): result.setdefault(key+1,value) return result my_dict = gen_dict() value_to_get = 'abcdef' for key,value in my_dict.iteritems(): if value == value_to_get: print key