order by in pandas code example

Example 1: df sort values

>>> df.sort_values(by=['col1'], ascending = False)
    col1 col2 col3
0   A    2    0
1   A    1    1
2   B    9    9
5   C    4    3
4   D    7    2
3   NaN  8    4

Example 2: 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 3: 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 4: sort by dataframe

DataFrame.sort_values(self, by, axis=0, ascending=True,
                      inplace=False, kind='quicksort',
                      na_position='last',
                      ignore_index=False)

# Example
df.sort_values(by=['ColToSortBy'])

Example 5: sort dataframe by column

df.sort_values(by='col1', ascending=False, na_position='first', inplace=True)

Example 6: sort a dataframe

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