emotion=["angry","happy","nervous","sad"]
元组0，1，2，3，或者逆序，-1-2-3-4
print(emotion[0:1])
['angry']
print(emotion[0:3])
['angry', 'happy', 'nervous']
打印小元组
print(emotion[3])
sad
print(emotion[-2])
nervous
打印元素
"hate"*5
'hatehatehatehatehate'
字符串多倍
"hate"+"you"
'hateyou'
字符串连接
"hate" in ("hate","you")
True
