Pandas DataFrame: shortcut not in list and KeyError
I'm trying to get the value of a specific cell.
main_id name code
0 1345 Jones 32
1 1543 Jack 62
2 9874 Buck 86
3 2456 Slim 94
I want the cell to say code = 94 since I already know the main_id, but nothing else.
raw_data = {'main_id': ['1345', '1543', '9874', '2456'],
'name': ['Jones', 'Jack', 'Buck', 'Slim'],
'code': [32, 62, 86, 94]}
df=pd.DataFrame(raw_data, columns = ['main_id', 'name', 'code'])
v=df.loc[str(df['main_id']) == str(2456)]['code'].values
print(df.loc['name'])
print (df.loc ['name']) claims the label is not in the index
and v = df.loc [str (df ['main_id']) == str (2456)] ['code']. values says 'KeyError False'
source to share
df.loc['name']
Raises a KeyError because it is name
not in the index; it is in columns. When you use loc
, the first argument is for the index. You can use df['name']
or df.loc[:, 'name']
.
You can also pass boolean arrays in loc
(for both index and columns). For example,
df.loc[df['main_id']=='2456']
Out:
main_id name code
3 2456 Slim 94
You can also select a specific column for this:
df.loc[df['main_id']=='2456', 'code']
Out:
3 94
Name: code, dtype: int64
With boolean indices, the returned object will always be Series, even if you only have one value. This way you can access the underlying array and select the first value:
df.loc[df['main_id']=='2456', 'code'].values[0]
Out:
94
source to share