LeetCode Ransom Note

class Solution(object):    def canConstruct(self, ransomNote, magazine):        """        :type ransomNote: str        :type magazine: str        :rtype: bool        """        magazine_k_v = {}        for i in magazine:            t = magazine_k_v.get(i)            if t == None:                magazine_k_v[i]=1            else:                magazine_k_v[i]+=1        for j in ransomNote:            t = magazine_k_v.get(j)            if t == None:                return False            elif t == 0:                return False            else:                magazine_k_v[j]=t-1        return True