python学习d1

一.1.算术运算符

>>> print (1+1,2-2,3*3,4/4)
2 0 9 1.0
>>> 

传统除法输出的是浮点数

>>> print (2**2,24//7,8%3)
4 3 2
>>> 

2.比较运算符
等于是==不是=，=是赋值

>>> print(1=1)
SyntaxError: expression cannot contain assignment, perhaps you meant "=="?
>>> print(1==1)
True
>>> 

3.类型转换`

>>> x=7.2
>>> int(x)
7
>>> str(x)
'7.2'
>>> repr(x)
'7.2'

二.位运算
作业
def singleNumber(self, nums):
“”"
:type nums: List[int]
:rtype: int
“”"
k = 0
for i in nums:
k ^= i
print k
return k