调用函数时将列表转换为 *args [英] Converting list to *args when calling function
问题描述
在 Python 中,如何将列表转换为 *args
?
In Python, how do I convert a list to *args
?
我需要知道,因为函数
scikits.timeseries.lib.reportlib.Report.__init__(*args)
想要几个 time_series 对象作为 *args
传递,而我有一个时间序列对象列表.
wants several time_series objects passed as *args
, whereas I have a list of timeseries objects.
推荐答案
您可以在可迭代对象之前使用 *
运算符以在函数调用中扩展它.例如:
You can use the *
operator before an iterable to expand it within the function call. For example:
timeseries_list = [timeseries1 timeseries2 ...]
r = scikits.timeseries.lib.reportlib.Report(*timeseries_list)
(注意timeseries_list
之前的*
)
来自 python 文档:
如果函数调用中出现语法*expression,则表达式必须评估为可迭代的.来自这个迭代的元素被处理好像它们是附加的位置参数;如果有位置参数 x1、...、xN 和表达式的计算结果为序列 y1, ..., yM,这相当于调用了 M+N 个位置参数 x1, ..., xN, y1, ..., yM.
If the syntax *expression appears in the function call, expression must evaluate to an iterable. Elements from this iterable are treated as if they were additional positional arguments; if there are positional arguments x1, ..., xN, and expression evaluates to a sequence y1, ..., yM, this is equivalent to a call with M+N positional arguments x1, ..., xN, y1, ..., yM.
这也在 python 教程中包含在标题为 解包参数列表,其中还展示了如何使用 **
运算符对关键字参数的字典执行类似的操作.
This is also covered in the python tutorial, in a section titled Unpacking argument lists, where it also shows how to do a similar thing with dictionaries for keyword arguments with the **
operator.
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