如何正确构造具有单个出口的递归函数？

Question

我编写了一个递归函数来增强 pandas.DataFrame.describe。它将峰度和偏斜添加为行。它还创建了第二个描述表来转置第一个描述表，以便您获得汇总统计数据的摘要。

它工作得很好，只是我不喜欢编写具有多个出口的函数。我尝试用一个 return 语句编写它（请参阅注释掉的部分），但它会在一个表中创建两个转置表。正确，但太多了。

def get_better_desc(df, recursions: int = 1):

    '''Adds kurtosis and skew to pandas.DataFrame.describe output. And, creates

    second transposed version of this table called on itself for summary stats

    of summary stats.

    Parameters:

        df: pandas.DataFrame, or Series but its super_desc isn't so meaningful.

        recursions: integer number of times to apply recursively to create

            super_desc. Default value of 1 is all that is necessary.

    Returns:

        better_desc: pandas.Dataframe (or Series) with kurtosis and skew added.

        super_desc: pandas.DataFrame (or Series) of better_desc transposed and

            made into a better_desc itself.'''

    

    kurt = df.kurtosis()

    kurt.name = 'kurt'

    skew = df.skew()

    skew.name = 'skew'

    better_desc = df.describe().append([kurt, skew])

    

    if recursions > 0:

        super_desc = get_better_desc(better_desc.transpose(),

                                     recursions=(recursions - 1))

        return better_desc, super_desc

    else:

        return better_desc

#     if recursions > 0:

#         super_desc = get_better_desc(better_desc.transpose(),

#                                      recursions=(recursions - 1))

#     else:

#         super_desc = better_desc

    

#     return better_desc, super_desc

Answer 1

该函数返回两个数据帧，如果您只将其分配给一个变量，而不是忽略第二个返回值，它会将两者分配给该变量。在递归调用中，您只需指定第一个表，即 returns 列表中的第一个元素[0]。...if recursions > 0:&nbsp; &nbsp; &nbsp; &nbsp; super_desc = get_better_desc(better_desc.transpose(),&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;recursions=(recursions - 1))[0] #<=&nbsp; &nbsp; else:&nbsp; &nbsp; &nbsp; &nbsp; super_desc = better_desc&nbsp; &nbsp;&nbsp;&nbsp; &nbsp; return better_desc, super_desc