python day02--运算符，编码

一.格式化输出

%s: 字符串的占位符, 可以放置任何内容(数字)
%d: 数字的占位符

age="18"
name="小明"
print("我叫%s"% "小明")
print("我叫%s,今年%s岁" % (name,age) )

二.常见运算符

计算机常用的数据
print(2**0) # 代表2的0次方
print(2**1) #2的一次方
print(2**2) #同上
print(2**3)
print(2**4)
print(2**5)
print(2**6)
print(2**7)
print(2**8)
print(2**9)
print(2**10)

赋值运算.
a = 10
a += 20     # 相当于a = a + 20
print(a)

print(not not not not not not False)

(and ,or, not) 同时存在. 先算括号, 然后算not, 然后算and , 最后算or
print(3>4 or 4<3  and  1==1) # False

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)
print(not  2 > 1  and 3 < 4  or 4 > 5  and 2 > 1  and 9 > 8  or 7 < 6) # F

x or y 如果x==0 那么就是y, 否则是x
print(1 or 2)   # 1
print(2 or 3)   # 2
print(0 or 3)   # 3
print(0 or 4)   # 4

print(0 or 1 or 3 or 0 or 5)    #
print(1 and 2)  # 2
print(2 and 0)  # 0
print(0 and 3)  # 0
print(0 and 4)  # 0

print(0 or 4 and  3 or 7 or 9 and  6)

print(2 > 3 and 3)      # false相当于0
print(2 < 1 and 4 > 6 or 3 and 4 > 5 or 6)#结果可能是数字也可能是True和False