将交互式python中的默认repr从builtins.repr更改为reprlib.repr

Question

在交互式Python提示符上，当我没有将表达式foo的输出绑定到名称时，Python会将builtins.repr(foo)的输出写入终端。

在较新版本的Python中，存在不会在屏幕上显示具有长字符串表示的对象的an alternative repr implementation，如下所示：

In [297]: import random, string, reprlib

In [298]: long_str = ''.join(random.choice(string.ascii_letters) for _ in range(1000))

In [299]: print(repr(long_str))
'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'

In [300]: print(reprlib.repr(long_str))
'LcOKLSfEifoh...CKmpTICujAJsA'

In [301]: long_str
Out[301]: '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'

我可以以某种方式告诉Python使用reprlib.repr而不是builtin.repr在交互式提示符中表示未分配的输出吗？我对适用于任何Python shell的答案感兴趣，或者对至少适用于IPython的答案感兴趣。

Answer 1

你要找的可能是sys.display_hook：http://docs.python.org/2/library/sys.html#sys.displayhook。