Pandas：如何使用 LocIndexer？
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Pandas: How to use LocIndexer?
提问by Liam Pieri
I am trying to figure out how to use a Locindexer object to select a subset of a dataframe.
我想弄清楚如何使用 Locindexer 对象来选择数据帧的子集。
For example
例如
var = df.loc(df['rating'] == 4)
var = df.loc(df['rating'] == 4)
Returns as
返回为
pandas.core.indexing._LocIndexer
pandas.core.indexing._LocIndexer
How do I use a LocIndexer to select the a subset of my dataframe?
如何使用 LocIndexer 选择数据帧的子集？
回答by Vaishali
You are calling it as a function. For indexing, you use [].
您将其作为函数调用。对于索引，您使用 []。
df.loc[df['rating'] == 4]
would return the row/rows in which value of column rating is 4.
将返回列评级值为 4 的行/行。
回答by Onel Harrison
You shouldn't have any problems selecting a subset using the code below.
使用下面的代码选择子集应该不会有任何问题。
subset = df.loc[(df['rating'] == 4)]
回答by 2Obe
Furthermore if you have selected the row with:
此外，如果您选择了以下行：
subset = df.loc[(df['rating'] == 4)]
you can acces a special column of this row with
您可以访问此行的特殊列
1.
1.
df.loc[(df['rating'] == 4)]["column]
2.
2.
subset["column"]
