参考代码:

class Solution:
    def capitalizesFirst(self, s):
        n = len(s)
        s1 = list(s)
        if s1[0] >= 'a' and s1[0] <= 'z':
            s1[0] = chr(ord(s1[0]) - 32)
        for i in range(1, n):
            if s1[i -1] == '' and s1[i] != '':
                s1[i] = chr(ord(s1[i]) - 32)
        return ''.join(s1)