Pandas DataFrame set_index() Method

Example

Make the "name" column become the index of the DataFrame:

import pandas as pd

data = {
"name": ["Sally", "Mary", "John", "Monica"],
"age": [50, 40, 30, 40],
"qualified": [True, False, False, False]
}

df = pd.DataFrame(data)

newdf = df.set_index('name')

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Definition and Usage

The set_index() method allows one or more column values become the row index.

Syntax

dataframe.set_index(keys, drop, append, inplace, verify_integrity)

Parameters

The drop, append, inplace, verify_integrity parameters are keyword arguments.

Parameter	Value	Description
keys		Required. String or list containing column labels and/or column keys
drop	`True False`	Optional, default True. Set to False the column you set as row index, should still be kept as a column
append	`True False`	Optional, default False. Set to True if the new row index should be appended to the existing (by default the existing index gets overwritten)
inplace	`True False`	Optional, default False. If True: the operation is done on the current DataFrame. If False: returns a copy where the operation is done.
verify_integrity	`True False`	Optional, default False. Specifies if the new indexes should be checked for duplicates or not

Return Value

A DataFrame with the result, or None if the inplace parameter is set to True.

❮ DataFrame Reference