Extract values in Pandas value_counts()

问题

Say we have used pandas dataframe[column].value_counts() which outputs:

 apple   5 
 sausage 2
 banana  2
 cheese  1

How do you extract the values in the order same as shown above from max to min ?

e.g: [apple,sausage,banana,cheese]

回答1:

Try this:

dataframe[column].value_counts().index.tolist()
['apple', 'sausage', 'banana', 'cheese']

回答2:

#!/usr/bin/env python

import pandas as pd

# Make example dataframe
df = pd.DataFrame([(1, 'Germany'),
                   (2, 'France'),
                   (3, 'Indonesia'),
                   (4, 'France'),
                   (5, 'France'),
                   (6, 'Germany'),
                   (7, 'UK'),
                   ],
                  columns=['groupid', 'country'],
                  index=['a', 'b', 'c', 'd', 'e', 'f', 'g'])

# What you're looking for
values = df['country'].value_counts().keys().tolist()
counts = df['country'].value_counts().tolist()

Now, print(df['country'].value_counts()) gives:

France       3
Germany      2
UK           1
Indonesia    1

and print(values) gives:

['France', 'Germany', 'UK', 'Indonesia']

and print(counts) gives:

[3, 2, 1, 1]

回答3:

If anyone missed it out in the comments, try this:

dataframe[column].value_counts().to_frame()

回答4:

First you have to sort the dataframe by the count column max to min if it's not sorted that way already. In your post, it is in the right order already but I will sort it anyways:

dataframe.sort_index(by='count', ascending=[False])
    col     count
0   apple   5
1   sausage 2
2   banana  2
3   cheese  1

Then you can output the col column to a list:

dataframe['col'].tolist()
['apple', 'sausage', 'banana', 'cheese']

来源：https://stackoverflow.com/questions/35523635/extract-values-in-pandas-value-counts

标签

python

pandas

dataframe

series