1, print ---- unimportant
py2:print'xx'
py3:print('xx')
2, an important inheritance -----
py2: Classic / new class
py3: new class
3, coding & string: ---- important
String:
py2: unicode v = u "xxx" stored in unicode with essentially
(Str / bytes) v = "xxx" stored in the nature of bytes
py3: str v = essentially "xxx" stored in unicode with
Essentially bytes v = b "xxx" stored in bytes
coding:
py2: default ascii
py3: utf8 default
4, input ---- unimportant
py2:v1 = raw_input('xx:')
py3:v1 = input('xx:')
5, range: ---- less important
py2:range/xrange
py3: range --- (py3 range equivalent to the range of xrange.py2 Py2 range corresponding to the length is created directly in memory)