在列表 [data] = self.read() 中声明一个 python 变量？

Question

在研究Odoo的开源repo时，我发现了一行我看不懂的代码，如下所示

[data] = self.read()

在那里找到 https://github.com/odoo/odoo/blob/8f297c9d5f6d31370797d64fee5ca9d779f14b81/addons/hr_holidays/wizard/hr_holidays_summary_department.py#L25

我真的很想知道你为什么要把变量放在列表中

Answer 1

似乎确保 [data] 是一个项目的可迭代对象，因此从 self.read()

中解压第一个值

不能赋值给不可迭代对象

>>> [data] = 1
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: cannot unpack non-iterable int object

适用于可迭代类型，但长度必须等于 1

>>> [data] = {'some':2}
>>> data
'some'
>>> [data] = {'foo':2, 'bar':3}
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: too many values to unpack (expected 1)
>>> [data] = [1]
>>> data
1
>>> [data] = [[1]]
>>> data
[1]
>>> [data] = [1, 2]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: too many values to unpack (expected 1)
>>> [data] = []
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: not enough values to unpack (expected 1, got 0)

在列表 [data] = self.read() 中声明一个 python 变量？

declaring a python variable in a list [data] = self.read()?

python-3.x

odoo