I have the following dataframe
PopEst Continent
Country
China 1.367645e+09 Asia
United States 3.176154e+08 North America
Japan 1.274094e+08 Asia
United Kingdom 6.387097e+07 Europe
Russian Federation 1.435000e+08 Europe
Canada 3.523986e+07 North America
Germany 8.036970e+07 Europe
India 1.276731e+09 Asia
France 6.383735e+07 Europe
South Korea 4.980543e+07 Asia
Italy 5.990826e+07 Europe
Spain 4.644340e+07 Europe
Iran 7.707563e+07 Asia
Australia 2.331602e+07 Australia
Brazil 2.059153e+08 South America
And based on the continent column, I need to add 4 new columns: Count (Nr of countries in the continent) Then Mean, Std, and Sum for the column PopEst
I tried the following:
df.groupby('Continent').aggregate({'size': 'count',
'sum': 'sum',
'mean': 'mean',
'std': 'std'})
but then I get this error:
---------------------------------------------------------------------------
KeyError Traceback (most recent call last)
/opt/conda/lib/python3.7/site-packages/pandas/core/indexes/base.py in get_loc(self, key, method, tolerance)
2889 try:
-> 2890 return self._engine.get_loc(key)
2891 except KeyError:
pandas/_libs/index.pyx in pandas._libs.index.IndexEngine.get_loc()
pandas/_libs/index.pyx in pandas._libs.index.IndexEngine.get_loc()
pandas/_libs/hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()
pandas/_libs/hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()
KeyError: 'size'
During handling of the above exception, another exception occurred:
KeyError Traceback (most recent call last)
<ipython-input-40-ef7220b45d9d> in <module>
23 'sum': 'sum',
24 'mean': 'mean',
---> 25 'std': 'std'})
26
27 print(df)
