[python] how to sort pandas dataframe from one column

I have a data frame like this:

print(df)

        0          1     2
0   354.7      April   4.0
1    55.4     August   8.0
2   176.5   December  12.0
3    95.5   February   2.0
4    85.6    January   1.0
5     152       July   7.0
6   238.7       June   6.0
7   104.8      March   3.0
8   283.5        May   5.0
9   278.8   November  11.0
10  249.6    October  10.0
11  212.7  September   9.0

As you can see, months are not in calendar order. So I created a second column to get the month number corresponding to each month (1-12). From there, how can I sort this data frame according to calendar months' order?

I tried the solutions above and I do not achieve results, so I found a different solution that works for me. The ascending=False is to order the dataframe in descending order, by default it is True. I am using python 3.6.6 and pandas 0.23.4 versions.

final_df = df.sort_values(by=['2'], ascending=False)

You can see more details in pandas documentation here.

This worked for me

df.sort_values(by='Column_name', inplace=True, ascending=False)

Using column name worked for me.

sorted_df = df.sort_values(by=['Column_name'], ascending=True)

Here is template of sort_values according to pandas documentation.

DataFrame.sort_values(by, axis=0,
                          ascending=True,
                          inplace=False,
                          kind='quicksort',
                          na_position='last',
                          ignore_index=False, key=None)[source]

In this case it will be like this.

df.sort_values(by=['2'])

API Reference pandas.DataFrame.sort_values

This one worked for me:

df=df.sort_values(by=[2])

Whereas:

df=df.sort_values(by=['2']) 

is not working.

Panda's sort_values does the work.

If one doesn't intends to keep the same variable name, don't forget the inplace=True (this performs the operation in-place)

df.sort_values(by=['2'], inplace=True)

One might as well assigning the change (sort) to a variable, that may have the same name as the df as

df = df.sort_values(by=['2'])

Forgetting the steps mentioned above may lead one (as this user) to not be able to get the expected result.

Note that if one wants in descending order, one needs to pass ascending=False, such as

df = df.sort_values(by=['2'], ascending=False)

Just as another solution:

Instead of creating the second column, you can categorize your string data(month name) and sort by that like this:

df.rename(columns={1:'month'},inplace=True)
df['month'] = pd.Categorical(df['month'],categories=['December','November','October','September','August','July','June','May','April','March','February','January'],ordered=True)
df = df.sort_values('month',ascending=False)

It will give you the ordered data by month name as you specified while creating the Categorical object.

Just adding some more operations on data. Suppose we have a dataframe df, we can do several operations to get desired outputs

ID         cost      tax    label
1       216590      1600    test      
2       523213      1800    test 
3          250      1500    experiment

(df['label'].value_counts().to_frame().reset_index()).sort_values('label', ascending=False)

will give sorted output of labels as a dataframe

    index   label
0   test        2
1   experiment  1