Python 数据帧转换。一次应用几个算术运算

我有一个如下所示的数据框：

我想应用一些操作使其看起来像这样：

在1）电影中，我将Movies.count（）放在每个演员身上，2）评级变成独特电影的平均评级，3）按演员对独特电影的投票进行汇总

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请帮助了解如何进行此转换。谢谢。

首先，您可以按名称和电影分组以删除重复项，然后按名称分组以聚合其余项：

In [25]: films.groupby(["Name", "Movie"]).first().reset_index().groupby("Name")
    ...: .agg({"Movie": "count", "Rating": "mean", "Votes": "sum"})
Out[25]:
                   Movie  Rating  Votes
Name
Brad Pitt              3    7.60    250
John Travolta          1    7.90     85
Leonardo DiCaprio      2    8.65    280
Rowan Atkinson         1    9.00    150
Uma Thurman            1    7.90     85

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首先，您可以按名称和电影分组以删除重复项，然后仅按名称分组以聚合其余项：

In [25]: films.groupby(["Name", "Movie"]).first().reset_index().groupby("Name")
    ...: .agg({"Movie": "count", "Rating": "mean", "Votes": "sum"})
Out[25]:
                   Movie  Rating  Votes
Name
Brad Pitt              3    7.60    250
John Travolta          1    7.90     85
Leonardo DiCaprio      2    8.65    280
Rowan Atkinson         1    9.00    150
Uma Thurman            1    7.90     85

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我将首先处理重复项，然后分组，而不是使用嵌套的groupby

%timeit films.drop_duplicates(['Movie', 'Name']).groupby(['Name']).agg({'Movie' : 'count', 'Rating' : 'mean', 'Votes' : 'sum'})
2.55 ms ± 122 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)


%timeit films.groupby(["Name", "Movie"]).first().reset_index().groupby("Name").agg({"Movie": "count", "Rating": "mean", "Votes": "sum"})
6.92 ms ± 143 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)


                   Movie    Rating  Votes
Name            
Brad Pitt           3       7.60    250
John Travolta       1       7.90    85
Leonardo DiCaprio   2       8.65    280
Rowan Atkinson      1       9.00    150
Uma Thurman         1       7.90    85

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我将首先处理重复项，然后分组，而不是使用嵌套的groupby

%timeit films.drop_duplicates(['Movie', 'Name']).groupby(['Name']).agg({'Movie' : 'count', 'Rating' : 'mean', 'Votes' : 'sum'})
2.55 ms ± 122 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)


%timeit films.groupby(["Name", "Movie"]).first().reset_index().groupby("Name").agg({"Movie": "count", "Rating": "mean", "Votes": "sum"})
6.92 ms ± 143 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)


                   Movie    Rating  Votes
Name            
Brad Pitt           3       7.60    250
John Travolta       1       7.90    85
Leonardo DiCaprio   2       8.65    280
Rowan Atkinson      1       9.00    150
Uma Thurman         1       7.90    85

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令人惊叹的！谢谢！令人惊叹的！谢谢！