字符串操作：求字符串中长度最长的单词

#求字符串中长度最长的单词，这是一道贝壳测试开发职位面试题

letters='you are very beautiful'
letter_dic={}
max_length=0
for letter in letters.split(' '):
    if letter in letter_dic:
        letter_dic[letter]=len(letter)
    else:
        letter_dic[letter]=1
for k,v in letter_dic.items():

       max_length=letter_dic[k]
        if letter_dic[k]>=max_length:
              max_length=letter_dic[k]
              max_length_letter=k
           else:
               continue
print(max_length_letter,max_length)