ipython - 如果我在 iPython 中输入/，为什么会得到空元组？

Question

打开 iPython 并输入:

/

按 Enter 并想知道结果:

()

你不能分配它，我猜它与 shell 功能有关。

编辑:

您可以将其分配给:

 p = Out[xx]

但不是直接:

 p = / 

会给:

SyntaxError

它确实是一个空元组。

Answer 1

这是可调用对象/名称的便利功能。它不是空元组，而是括号完成。来自 iPython 的帮助系统 ( ? ):

• Auto-parentheses and auto-quotes (adapted from Nathan Gray's LazyPython)

  1. Auto-parentheses

     Callable objects (i.e. functions, methods, etc) can be invoked like this (notice the commas between the arguments)::

     In [1]: callable_ob arg1, arg2, arg3

     and the input will be translated to this::

     callable_ob(arg1, arg2, arg3)

     This feature is off by default (in rare cases it can produce undesirable side-effects), but you can activate it at the command-line by starting IPython with --autocall 1, set it permanently in your configuration file, or turn on at runtime with %autocall 1.

     You can force auto-parentheses by using '/' as the first character of a line. For example::

     In [1]: /globals # becomes 'globals()'