Python 从 Pandas 数据框中获取特定行作为系列

Get particular row as series from pandas dataframe

提问by Pratyush

How do we get a particular filtered row as series?

我们如何将特定的过滤行作为系列？

Example dataframe:

示例数据框：

>>> df = pd.DataFrame({'date': [20130101, 20130101, 20130102], 'location': ['a', 'a', 'c']})
>>> df
       date location
0  20130101        a
1  20130101        a
2  20130102        c

I need to select the row where locationis cas a series.

我需要选择该行，其中location是c一系列。

I tried:

我试过：

row = df[df["location"] == "c"].head(1)  # gives a dataframe
row = df.ix[df["location"] == "c"]       # also gives a dataframe with single row

In either cases I can't the row as series.

在任何一种情况下，我都不能将行作为系列。

采纳答案by Boud

Use the squeezefunction that will remove one dimension from the dataframe:

使用squeeze将从数据框中删除一维的函数：

df[df["location"] == "c"].squeeze()
Out[5]: 
date        20130102
location           c
Name: 2, dtype: object

DataFrame.squeezemethod acts the same way of the squeezeargument of the read_csvfunction when set to True: if the resulting dataframe is a 1-len dataframe, i.e. it has only one dimension (a column or a row), then the object is squeezed down to the smaller dimension object.

DataFrame.squeeze当设置为 时，方法的作用与函数的squeeze参数相同：如果结果数据帧是 1-len 数据帧，即它只有一个维度（一列或一行），则对象被压缩到较小的维度目的。read_csvTrue

In your case, you get a Series object from the DataFrame. The same logic applies if you squeeze a Panel down to a DataFrame.

在您的情况下，您从 DataFrame 获得一个 Series 对象。如果将 Panel 压缩为 DataFrame，则适用相同的逻辑。

squeeze is explicit in your code and shows clearly your intent to "cast down" the object in hands because its dimension can be projected to a smaller one.

挤压在您的代码中是明确的，并清楚地显示了您“放下”手中物体的意图，因为它的尺寸可以投影到更小的尺寸。

If the dataframe has more than one column or row, squeeze has no effect.

如果数据框有多于一列或多行，挤压无效。

回答by Roman Pekar

You can just take first row with integer indexing (iloc()function):

您可以使用整数索引（iloc()函数）获取第一行：

>>> df[df["location"] == "c"].iloc[0]
date        20130102
location           c
Name: 2, dtype: object