第七天-数据池/常量池 编码补充

 1 # id() 查看一个变量表示的值的内存地址
 2 a = 1000
 3 b = 1000
 4 c = "lijie"
 5 print(id(a)) # 2602674608112  内存地址
 6 print(id(b)) # 2602674608112
 7 print(id(c)) #  2602703864248
 8 
 9 # == 判断左右两边的值是否一致
10 print(a == b)  # 判断左右两边的值
11 print(a == c)
12 
13 # is 判断左右两边的内容地址是否一致
14 print(a is b)  # 判断左右两边内容地址
15 print(b is c)

1 # 单纯的创建变量。都是有缓存的
2 a = 49876
3 b = 49876
4 print(a is b)  # True
5 a = 49786*20
6 b = 49786*20
7 print(a is b) # True

1 # 注意 在命令行中(command模式) 小数据池 int取值范围在[-5,256]
2 a = 2000
3 b = 2000
4 print(a is b) # 在py文件里面是True

 1 #.encode()  
 2 s = "嘿en哈"
 3 s0 = "JJ"
 4 bs = s.encode("utf-8") # 制定utf-8格式
 5 bs0 = s0.encode("utf-8")
 6 # 英文编码之后结果和源字符串一致.中文编码之后的结果根据编码不同.编码结果不同.
 7 print(bs0) # b'JJ' 英文编码后和原来一致
 8 print(bs)  # b'\xe5\x98\xbfen\xe5\x93\x88'  一个中文utf-8三字节
 9 bs0 = s0.encode("gbk")
10 bs = s.encode("gbk")
11 print(bs0) # b'JJ'
12 print(bs) # b'\xba\xd9en\xb9\xfe'  一个中文gbk 两字节

1 j = b'\xba\xd9en\xb9\xfe'
2 j1 = j.decode("gbk")
3 print(j1)

1 # 练习 把一个utf-8编码变成GBK编码
2 bm = b'\xe5\x98\xbfen\xe5\x93\x88'
3 
4 bm0 = bm.decode() # 先解码成Unicode
5 bm1 = bm0.encode("gbk") # 再编码成gbk
6 print(bm1)