python - 在列中添加值

Question

我有一个数据框 df，我想在 cast 和 genres 列中添加 '/'这样每个单元格包含3个'/'

id  movie      cast      genres  runtime
1   Furious    a/b/c/d   a/b        23
2   Minions    a/b/c     a/b/c      55
3   Mission    a/b       a          67
4   Kingsman   a/b/c/d   a/b/c/d    23
5   Star Wars  a         a/b/c      45

所以，它的输出看起来像这样

id  movie      cast      genres  runtime
1   Furious    a/b/c/d   a/b//      23
2   Minions    a/b/c/    a/b/c/     55
3   Mission    a/b//     a///       67
4   Kingsman   a/b/c/d   a/b/c/d    23
5   Star Wars  a///      a/b/c/     45

Answer 1

这是定义自定义函数的一种方法:

def add_values(df, *cols):
    for col in cols:
        # amount of "/" to add at each row
        c = df[col].str.count('/').rsub(3)
        # translate the above to as many "/" as required
        ap = [i * '/' for i in c.tolist()]
        # Add the above to the corresponding column
        df[col] = [i + j for i,j in zip(df[col], ap)]
    return df

add_values(df, 'cast', 'genres')

   id     movie     cast   genres  runtime
0   1   Furious  a/b/c/d    a/b//       23
1   2   Minions   a/b/c/   a/b/c/       55
2   3   Mission    a/b//     a///       67
3   4  Kingsman  a/b/c/d  a/b/c/d       23
4   5  StarWars     a///   a/b/c/       45