pandas sort series code example

Example 1: sorting by column in pandas

#Python, Pandas
#Sorting dataframe df on the values of a column col1
#Temporary
df.sort_values(by=["col1"]) 

#Permanent
df.sort_values(by=["col1"], inplace = True)

Example 2: how to sort in pandas

// Single sort 
>>> df.sort_values(by=['col1'],ascending=False)
// ascending => [False(reverse order) & True(default)]
// Multiple Sort
>>> df.sort_values(by=['col1','col2'],ascending=[True,False])
// with apply() 
>>> df[['col1','col2']].apply(sorted,axis=1)
// axis = [1 & 0], 1 = 'columns', 0 = 'index'

Example 3: sort values pandas

>>> df = pd.DataFrame({
...     'col1': ['A', 'A', 'B', np.nan, 'D', 'C'],
...     'col2': [2, 1, 9, 8, 7, 4],
...     'col3': [0, 1, 9, 4, 2, 3],
...     'col4': ['a', 'B', 'c', 'D', 'e', 'F']
... })
>>> df
  col1  col2  col3 col4
0    A     2     0    a
1    A     1     1    B
2    B     9     9    c
3  NaN     8     4    D
4    D     7     2    e
5    C     4     3    F


df.sort_values(by=['col1'])
  col1  col2  col3 col4
0    A     2     0    a
1    A     1     1    B
2    B     9     9    c
5    C     4     3    F
4    D     7     2    e
3  NaN     8     4    D

Example 4: sort a dataframe

sort_na_first = gapminder.sort_values('lifeExp',na_position='first')

Example 5: how to sort the dataframe in python

import pandas as pd
df1=pd.read_csv("registration.csv")
df2=pd.read_csv("payment.csv")
df=pd.merge(df1,df2)
print(df.iloc[:,[0,1,3,4]].to_string(index=False))