python3 vs python2

>>> import sys
>>> print("fatal error",file=sys.stderr)
fatal error
>>> fp=open(r"d:\\a.txt",'w')
>>> print("python3",file=fp)
>>> fp.close()
>>> print("There are <", 2**32, "> possibilities!", sep=" ") 默认空格符为分隔符
There are < 4294967296 > possibilities!
>>> print("There are <", 2**32, "> possibilities!", sep="") 自定义，不用空格分开
There are <4294967296> possibilities!
>>> 

>>> import sys
>>> print(sys.getdefaultencoding())
utf-8
>>> "中文"
'中文'

>>> import sys
>>> sys.getdefaultencoding()
'ascii'
>>> "中文"
'\xd6\xd0\xc\xc4'

>>> a,*b,c= range(5)
>>> a,b,c
(0, [1, 2, 3], 4)