比较 pandas 数据框中的两列和 return 差异

Question

我正在比较两个 excel 工作表的内容，我已将其转换为 pandas 数据框并将各列并排放置。

我已经创建了一些代码来比较两列并在下面给出输出，但是一些字符串包含大量文本所以我想显示仅差异.

+---------------------+-------------------------+---------------------------------------------+
|         Old         |           New           |                   Changes                   |
+---------------------+-------------------------+---------------------------------------------+
| Apple, Egg, Ham     | Apple, Egg, Norway, Ham | Apple, Egg, Ham --> Apple, Egg, Norway, Ham |
| Instagram, Facebook | Instagram, Twitter      | Instagram, Facebook --> Instagram, Twitter  |
+---------------------+-------------------------+---------------------------------------------+

最佳结果如下所示：

+---------------------+-------------------------+---------------------+
|         Old         |           New           |       Changes       |
+---------------------+-------------------------+---------------------+
| Apple, Egg, Ham     | Apple, Egg, Norway, Ham | +Norway             |
| Instagram, Facebook | Instagram, Twitter      | +Twitter, -Facebook |
+---------------------+-------------------------+---------------------+

第 1 行添加了挪威，第 2 行添加了 Twitter，第 2 行删除了 Facebook。

我该如何解决这个问题？

Answer 1

将值转换为集合，然后使用它们的差异，还在 f-string 中添加 + 和 -，并在最后一步加入 ,：

def f(x):
    old, new = set(x['Old'].split(', ')), set(x['New'].split(', '))
    d = old.difference(new)
    e = new.difference(old)
    return ', '.join([f'+{y}' for y in e] + [f'-{y}' for y in d])


df['Changes'] = df.apply(f, axis=1)
print (df)
                   Old                      New              Changes
0      Apple, Egg, Ham  Apple, Egg, Norway, Ham              +Norway
1  Instagram, Facebook       Instagram, Twitter  +Twitter, -Facebook

Answer 2

下面是我要走的路：

def find_diff(x):
    more = set(x.New.split(",")) - set(x.Old.split(","))
    less = set(x.Old.split(",")) - set(x.New.split(","))

    result = " ".join([f"+{x}" for x in more]) +", " + " ".join([f"-{x}" for x in less])
    return result

df.apply(find_diff, axis=1)

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