py3和py2的差别(补充)
python3:print('abc') python2: print 'abc'
python3: range() python2 xrange() 生成器
python3:input() python2:raw_input()
python3:print('abc') python2: print 'abc'
python3: range() python2 xrange() 生成器
python3:input() python2:raw_input()