`>>>和有什么不一样?some_object`和`>>>在Python解释器中打印some_object`? [英] What is the difference between `>>> some_object` and `>>> print some_object` in the Python interpreter?

问题描述

在解释器中，您可以只写一个对象的名称，例如像这样的解释器提示符处的列表 a = [1、2、3，uhellö"] :

In the interpreter you can just write the name of an object e.g. a list a = [1, 2, 3, u"hellö"] at the interpreter prompt like this:

>>> a
[1, 2, 3, u'hell\xf6']

或者您可以这样做:

>>> print a
[1, 2, 3, u'hell\xf6']

似乎等同于列表.目前，我正在使用hdf5来管理一些数据，并且我意识到上述两种方法之间存在差异.鉴于:

which seems equivalent for lists. At the moment I am working with hdf5 to manage some data and I realized that there is a difference between the two methods mentioned above. Given:

with tables.openFile("tutorial.h5", mode = "w", title = "Some Title") as h5file:
    group = h5file.createGroup("/", 'node', 'Node information')
    tables.table = h5file.createTable(group, 'readout', Node, "Readout example")

print h5file

与

>>> h5file

所以我想知道是否有人可以解释这两种情况下Python的行为差异?

So I was wondering if someone could explain Python's behavioral differences in these two cases?

推荐答案

在终端中键入对象会调用 __ repr __()，它用于详细显示要打印的对象(明确).当您说出要打印"的内容时，您正在调用 __ str __()，因此要求提供人类可读的内容.

Typing an object into the terminal calls __repr__(), which is for a detailed representation of the object you are printing (unambiguous). When you tell something to 'print', you are calling __str__() and therefore asking for something human readable.

Alex Martelli在此处作了很好的解释.线程中的其他响应也可能说明差异.

Alex Martelli gave a great explanation here. Other responses in the thread might also illuminate the difference.

例如，看看日期时间对象.

For example, take a look at datetime objects.

>>> import datetime
>>> now = datetime.datetime.now()

比较...

>>> now
Out: datetime.datetime(2011, 8, 18, 15, 10, 29, 827606)

到...

>>> print now
Out: 2011-08-18 15:10:29.827606

希望这使它更加清晰！

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