set_index
Signature:
df.set_index(
['keys', 'drop=True', 'append=False', 'inplace=False', 'verify_integrity=False'],
)
Docstring:
Set the DataFrame index (row labels) using one or more existing
columns. By default yields a new object.
Parameters
----------
keys : column label or list of column labels / arrays
drop : boolean, default True
Delete columns to be used as the new index
append : boolean, default False
Whether to append columns to existing index
inplace : boolean, default False
Modify the DataFrame in place (do not create a new object)
verify_integrity : boolean, default False
Check the new index for duplicates. Otherwise defer the check until
necessary. Setting to False will improve the performance of this
method
Examples
--------
>>> df = pd.DataFrame({'month': [1, 4, 7, 10],
... 'year': [2012, 2014, 2013, 2014],
... 'sale':[55, 40, 84, 31]})
month sale year
0 1 55 2012
1 4 40 2014
2 7 84 2013
3 10 31 2014
Set the index to become the 'month' column:
>>> df.set_index('month')
sale year
month
1 55 2012
4 40 2014
7 84 2013
10 31 2014
Create a multi-index using columns 'year' and 'month':
>>> df.set_index(['year', 'month'])
sale
year month
2012 1 55
2014 4 40
2013 7 84
2014 10 31
Create a multi-index using a set of values and a column:
>>> df.set_index([[1, 2, 3, 4], 'year'])
month sale
year
1 2012 1 55
2 2014 4 40
3 2013 7 84
4 2014 10 31
Returns
-------
dataframe : DataFrame
File: c:\users\lenovo\anaconda3\lib\site-packages\pandas\core\frame.py
Type: method