python小练习-找出字符串中的子字符串

 1 #方法1
 2 #找出字符串中以a开头，以b结尾的所有子串
 3 def find_substr(string):
 4     result = []
 5     for i,s in enumerate(string):
 6         for j,e in enumerate(string):
 7             if s == ‘a‘ and e == ‘b‘ and j > i:
 8                 result.append(string[i:j+1])
 9     new_result = set(result)
10     return new_result

 1 #方法2
 2 def serach_index(target,string):
 3     i = 0
 4     index = []
 5     for str in string:
 6         if str == target:
 7             s = string.index(target,i)
 8             i = s + 1
 9             index.append(s)
10     return index
11 
12 def find_str(start_list,end_list,string):
13     result = []
14     for s in start_list:
15         for e in end_list:
16             if s < e:
17                 result.append(string[s:e+1])
18     new_result = set(result)
19     return new_result
20 
21 def findall(string):
22     a = serach_index(‘a‘,string)
23     b = serach_index(‘b‘,string)
24     return find_str(a,b,string)

1 string = ‘aaabbbabab‘
2 #调用函数
3 findall(string)
4 
5 #或者
6 
7 find_substr(string)