String的方法capitalize

官方解释：Return a copy of the string with its first character capitalized and the rest lowercased.（返回字符串的副本，其首字符大写，其余字符小写。）

• 使用方法：

>>> s1 = 'python最牛掰'
>>> ret1 = s1.capitalize()
>>> print(ret1)
Python最牛掰