day02_字符编码

1.编码格式化输出:%s   %d   %

print("姓名%s,年龄%d"%(tom,12))

2.编码:

ascii 只显示英文,特殊字符,数字   00000000    八位 2**8=256  一开始7位,多预留一位

万国码:Unicode   最开始16位,中文不够(九万多字,最少需要3个字节) 分配32位 4个字节

utf-8:最少用一个字节,8位表示一个英文

  欧洲16位,2个字节

  亚洲24位,3个字节

gbk:用于中文(2个字节)与英文 

1bit 8bit = 1bytes
1byte 1024byte = 1KB
1KB 1024kb = 1MB
1MB 1024MB = 1GB
1GB 1024GB = 1TB

3.逻辑运算符

#and or not
#优先级,()> not > and > or
# print(2 > 1 and 1 < 4)
# print(2 > 1 and 1 < 4 or 2 < 3 and 9 > 6 or 2 < 4 and 3 < 2)
# T or T or F
#T or F
# print(3>4 or 4<3 and 1==1) # F
# print(1 < 2 and 3 < 4 or 1>2) # T
# print(2 > 1 and 3 < 4 or 4 > 5 and 2 < 1) # T
# print(1 > 2 and 3 < 4 or 4 > 5 and 2 > 1 or 9 < 8) # F
# print(1 > 1 and 3 < 4 or 4 > 5 and 2 > 1 and 9 > 8 or 7 < 6) # F
# print(not 2 > 1 and 3 < 4 or 4 > 5 and 2 > 1 and 9 > 8 or 7 < 6) # F

#ps int ----> bool 非零转换成bool True 0 转换成bool 是False
# print(bool(2))
# print(bool(-2))
# print(bool(0))
# #bool --->int
# print(int(True)) # 1
# print(int(False)) # 0


'''x or y x True,则返回x'''                   and 与  or相反,返回y
# print(1 or 2) # 1
# print(3 or 2) # 3
# print(0 or 2) # 2
# print(0 or 100) # 100


# print(2 or 100 or 3 or 4) # 2

# print(0 or 4 and 3 or 2)
'''x and y x True,则返回y'''
# print(1 and 2)
# print(0 and 2)
print(2 or 1 < 3)
print(3 > 1 or 2 and 2)

原文地址:https://www.cnblogs.com/wzc27229/p/10915156.html