Palindrome Partitioning

def is_palindrome(s):
    if s[:]==s[::-1]:
        return True
    return False

def fun(i,s,cur,ans):
    if i==len(s):
        ans.append(cur)
    for end in range(i+1,len(s)+1):
        if is_palindrome(s[i:end]):
            fun(end,s,cur+[s[i:end]],ans)

class Solution:
    def partition(self, s: str) -> List[List[str]]:
        ans=[]
        fun(0,s,[],ans)
        return ans