Python 3.2 空闲与终端

Question

在 OSX 下的 python 3.2 中，如果我在 Idle 下运行“type(sys.stdin)”，我会得到一个奇怪的答案，如下所示

>>> type(sys.stdin)
<class 'idlelib.rpc.RPCProxy'>
>>> 

但是如果我在终端下重新运行相同的命令，我会得到:

>>> import sys
>>> type(sys.stdin)
<class '_io.TextIOWrapper'>
>>> 

我明白这是因为我在 IDLE 下运行它。但这不是误导吗？

我试图在 IDLE 中运行以下命令，并花了数小时试图理解为什么这不起作用。 (我还是个python菜鸟)

>>> w = sys.stdin.readlines()
Traceback (most recent call last):
  File "<pyshell#4>", line 1, in <module>
    w = sys.stdin.readlines()
AttributeError: readlines

但刚刚发现我在终端下工作正常。

>>> w = sys.stdin.readlines()
wow
ww
wewew
>>> 
>>> w
['wow\n', 'ww\n', 'wewew\n']
>>> 

这是一个错误吗？

Answer 1

这是一个已归档的 Python 错误:

http://bugs.python.org/issue9290

The fact that in IDLE sys.stdin is a idlelib.rpc.RPCProxy results in programs having different behavior in IDLE and in Command Line mode.

I noticed that when grading many students exercises in IDLE. Things like:

sys.stdin.readlines()

just don´t exists in IDLE, but are fully operational in Command Line mode.

In Command Line mode, sys.stdin is a file.

This is expected, as the manual (27.1) says that sys.stdin (and stdout and stderrr) are "File objects corresponding to the interpreter’s standard input"

There are also other "quirks".

I fell that is really strange that stdin has different behavior for the same program.

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请注意，这可能未修复，因为 readlines 通常没有用。相反，您可以只遍历文件对象本身:

for line in sys.stdin:
    ...