python字典序問題執行個體

本文執行個體講述了python字典序問題，分享給大家供大家參考。具體如下：

問題描述:

將字母從左向右的次序與字母表中的次序相同,且每個字元最大出現一次..例如:a,b,ab,bc,xyz等都是升序的字串.現對字母表A產生的所有長度不超過6的升序字串按照字典充排列並編碼如下:

1	2	..	26	27	28	...
a	b	..	z	ab	ac	..

對一個升序字串,迅速計算出它在上述字典中的編碼。

實現代碼如下:

import stringall_letter = string.ascii_lowercasedef 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

結果:83682　　

即abcdef在字典中的編碼。

希望本文所述對大家的Python程式設計有所協助。

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