python2.x ---> print不是个函数 ，无法使用help(print) 查看帮助
python3.x ----> print()是一个函数，查看帮助如下：
>>> help(print)
Help on built-in function print in module builtins:
print(...)
print(value, ..., sep=' ', end='
', file=sys.stdout, flush=False) #默认分割符合是以' '做分割，默认结束符合是以'
'换行分割的
Prints the values to a stream, or to sys.stdout by default.
Optional keyword arguments:
file: a file-like object (stream); defaults to the current sys.stdout.
sep: string inserted between values, default a space.
end: string appended after the last value, default a newline.
flush: whether to forcibly flush the stream.
使用print输入示例：
python2.x
>>> print("a")
a
>>> print "a"
a
>>> print "a","b"
a b
>>> print "小范"
小范
python3.x：
>>> print("a","b")
a b
>>> print("a","b",end="-------")
a b------->>>
>>> print("a","b",end="")
a b>>>
>>> print("小范")
小范