格式化输入/输出符

%d 十进制整形
%ld 十进制长整形
%s 字符串
%c 字符型
%f 浮点型

hilarious = 'False' #注意首字母大写
aaa = "lalalala"
joke_evaluation = "Isn't that joke so funny?! %seeeee%s"
print (joke_evaluation % (aaa,hilarious))

输出结果：
Isn’t that joke so funny?! lalalalaeeeeeFalse