pandas series to list

[metalray]

Dear Pandas Experts,
I signed up for an online training for python and one of the problems I have is that I got a series but should make a list out of it.

def answer_six():
    statewiththemost=census_df.groupby(['CTYNAME']).CENSUS2010POP.sum().nlargest(3)
    x=statewiththemost
    return x #cal, tex, ny
answer_six()

CTYNAME
California    37253956
Texas         25145561
New York      19378102
Name: CENSUS2010POP, dtype: int64

I need to create a list with the top 3 country names as shown. not their actual population.
I tried it with x.index[0] or x.[CTYNAME] but both do not work.
I would super appreciate any help how to extract this first "column" out of my series.

[wavic]

df_list = df['STYNAME'].tolist()

[zivoni]

x is pandas.Series,  it has just one "column",  "column" with names of states is index.

To extract it and convert to list use x.index.tolist()

[metalray]

Hi wavic and zivoni.
Many thanks for your quick replies.

When I try

df_list = x['CTYNAME'].tolist()

The error reads:
KeyError: 'CTYNAME'

[zivoni]

x is pd.Series, it has no key or  column named 'CITYNAME', it has

• index (with name 'CITYNAME') with values given by group variable (distinct CITYNAMEs)
  
• values equal to sums of CENSUS2010POP over groups given by CITYNAMEs
  

Simple example with fake data and different colnames:

Output:
In [1]: import pandas as pd

In [2]:  df = pd.DataFrame({'statename':['California', 'Texas', 'Nevada', 'Hawai', 'California', 'Hawai',
   ...:  'Texas'], 'census':[1312, 2343, 3771, 3411, 1211, 943, 2341]})

In [3]: df
Out[3]: 
   census   statename
0    1312  California
1    2343       Texas
2    3771      Nevada
3    3411       Hawai
4    1211  California
5     943       Hawai
6    2341       Texas

In [4]: x = df.groupby('statename').census.sum().nlargest(3)

In [5]: x
Out[5]: 
statename
Texas     4684
Hawai     4354
Nevada    3771
Name: census, dtype: int64

In [6]: largest_states = x.index.tolist()

In [7]: largest_states
Out[7]: ['Texas', 'Hawai', 'Nevada']

In [8]: x.name
Out[8]: 'census'

In [9]: x.index.name
Out[9]: 'statename'

[metalray]

I see. Awesome! Thank you so much.