Question

import pandas as pd
df = pd.DataFrame({'A':[1,2,3], 'B':[4,5,6]}, 
                  index=['first','second','third'])

从给定的行号列表中检索相应的索引很简单：

df.iloc[[1,2]].index

但是相反呢？假设我得到了一个列表['second','third']。如何从中返回df的行号0和1？

Answer 1

尝试：

df.index.get_indexer(['second', 'third'])

输出：

array([1, 2], dtype=int64)

Answer 2

我们也有<img src=[url] width=60% height=100%> /*relative::Let's say this set of images is in a div who's css height is 300px. The images width given as 60% matches exactly its pixel width, which is 180px.*/

get_indexer_for

对于获取值，只做索引切片就足够了，不需要过滤数据框

df.index.get_indexer_for(['second', 'third'])
Out[178]: array([1, 2], dtype=int32)

从熊猫中的给定索引中获取行号

2 个答案: