Truncated sentences of leetcode simple questions

subject

The sentence It's a list of words , Words in the list are separated by a single space , And there are no leading or trailing spaces . Each word is made up of English letters in upper and lower case only （ No punctuation ）.
for example ,“Hello World”、“HELLO” and “hello world hello world” It's all sentences .
Here is a sentence for you s​​​​​​ And an integer k​​​​​​ , Would you please s​​ truncation ​,​​​ Make the truncated sentence contain only front k​​​​​​ Word . return truncation s​​​​​​ After the sentence .
Example 1：
Input ：s = “Hello how are you Contestant”, k = 4
Output ：“Hello how are you”
explain ：
s The word in is [“Hello”, “how” “are”, “you”, “Contestant”]
front 4 The first word is [“Hello”, “how”, “are”, “you”]
therefore , Should return “Hello how are you”
Example 2：
Input ：s = “What is the solution to this problem”, k = 4
Output ：“What is the solution”
explain ：
s The word in is [“What”, “is” “the”, “solution”, “to”, “this”, “problem”]
front 4 The first word is [“What”, “is”, “the”, “solution”]
therefore , Should return “What is the solution”
Example 3：
Input ：s = “chopper is not a tanuki”, k = 5
Output ：“chopper is not a tanuki”
Tips ：
1 <= s.length <= 500
k The range of phi is zero [1, s Number of words in ]
s It's only made up of uppercase and lowercase letters and spaces
s Words in are separated by a single space
There are no leading or trailing spaces
source ： Power button （LeetCode）

Their thinking

   Traversal sentence , Then calculate the number of spaces , If the number of spaces is equal to k, You can cut sentences directly , otherwise k Greater than the number of words in the sentence , Return to the original sentence .

class Solution:
    def truncateSentence(self, s: str, k: int) -> str:
        count=0
        for i in range(len(s)):
            if s[i]==' ':
                count+=1
            if count==k:
                break
        return s[0:i] if i!=len(s)-1 else s