pandasは、ある列に基づいてソートする(sort_values)

10341 ワード

    : https://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.sort_values.html
df.sort_values(by="XXXX" , ascending=False) by     ascending
#coding=utf-8
import pandas as pd
import numpy as np
#        。
series=pd.Series([3,4,1,6],index=['b','a','d','c'])
frame=pd.DataFrame([[2,4,1,5],[3,1,4,5],[5,1,4,2]],columns=['b','a','d','c'],index=['one','two','three'])
print frame
print series
print 'series        :'
print series.sort_index()
print 'series       :'
print series.sort_values()
print 'dataframe           (       ,  ascending  ):'
print frame.sort_index(ascending=False)
print 'dataframe         :'
print frame.sort_index(axis=1)
print 'dataframe       :'
print frame.sort_values(by='a')
print '          :'
print frame.sort_values(by=['a','c'])

    :
       b  a  d  c
one    2  4  1  5
two    3  1  4  5
three  5  1  4  2
b    3
a    4
d    1
c    6
dtype: int64
series        :
a    4
b    3
c    6
d    1
dtype: int64
series       :
d    1
b    3
a    4
c    6
dtype: int64
dataframe           (       ,  ascending  ):
       b  a  d  c
two    3  1  4  5
three  5  1  4  2
one    2  4  1  5
dataframe         :
       a  b  c  d
dd = frame.sort_values(by='b')
Out[38]: 
       b  a  d  c
one    2  4  1  5
two    3  1  4  5
three  5  1  4  2
dataframe       :
       b  a  d  c
two    3  1  4  5
three  5  1  4  2
one    2  4  1  5
          :
       b  a  d  c
three  5  1  4  2
two    3  1  4  5
one    2  4  1  5