Pandas drop_duplicates - 类型错误：* 后的类型对象参数必须是序列，而不是映射
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Pandas drop_duplicates - TypeError: type object argument after * must be a sequence, not map
提问by user3939059
I have updated my question to provide a clearer example.
我已经更新了我的问题以提供更清晰的示例。
Is it possible to use the drop_duplicates method in Pandas to remove duplicate rows based on a column id where the values contain a list. Consider column 'three' which consists of two items in a list. Is there a way to drop the duplicate rows rather than doing it iteratively (which is my current workaround).
是否可以使用 Pandas 中的 drop_duplicates 方法根据值包含列表的列 id 删除重复的行。考虑由列表中的两个项目组成的“三”列。有没有办法删除重复的行而不是反复执行（这是我目前的解决方法）。
I have outlined my problem by providing the following example:
我通过提供以下示例概述了我的问题：
import pandas as pd
data = [
{'one': 50, 'two': '5:00', 'three': 'february'},
{'one': 25, 'two': '6:00', 'three': ['february', 'january']},
{'one': 25, 'two': '6:00', 'three': ['february', 'january']},
{'one': 25, 'two': '6:00', 'three': ['february', 'january']},
{'one': 90, 'two': '9:00', 'three': 'january'}
]
df = pd.DataFrame(data)
print(df)
one three two
0 50 february 5:00
1 25 [february, january] 6:00
2 25 [february, january] 6:00
3 25 [february, january] 6:00
4 90 january 9:00
df.drop_duplicates(['three'])
Results in the following error:
导致以下错误：
TypeError: type object argument after * must be a sequence, not map
回答by Matthew
I think it's because the list type isn't hashable and that's messing up the duplicated logic. As a workaround you could cast to tuple like so:
我认为这是因为列表类型不可散列，这会弄乱重复的逻辑。作为一种解决方法，您可以像这样转换为元组：
df['four'] = df['three'].apply(lambda x : tuple(x) if type(x) is list else x)
df.drop_duplicates('four')
one three two four
0 50 february 5:00 february
1 25 [february, january] 6:00 (february, january)
4 90 january 9:00 january
