python小练习-找出字符串中的子字符串

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

#方法2
def serach_index(target,string):
    i = 0
    index = []
    for str in string:
        if str == target:
            s = string.index(target,i)
            i = s + 1
            index.append(s)
    return index

def find_str(start_list,end_list,string):
    result = []
    for s in start_list:
        for e in end_list:
            if s < e:
                result.append(string[s:e+1])
    new_result = set(result)
    return new_result

def findall(string):
    a = serach_index('a',string)
    b = serach_index('b',string)
    return find_str(a,b,string)

string = 'aaabbbabab'
#调用函数
findall(string)

#或者

find_substr(string)