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How to Solve Python AttributeError: ‘DataFrame’ object has no attribute ‘ix’

by | Programming, Python, Tips

The Pandas method ix is deprecated as of version 0.20.0. If you want to index a DataFrame, you can use DataFrame.loc for positional indexing and DataFrame.iloc for label indexing.

This tutorial will go through how to solve this error with code examples.


AttributeError: ‘DataFrame’ object has no attribute ‘ix’

AttributeError occurs in a Python program when we try to access an attribute (method or property) that does not exist for a particular object. The part of the error ‘DataFrame’ object has no attribute ‘ix‘ tells us that the DataFrame object we are handling does not have the ix method as an attribute. The ix() method is deprecated as of version 0.20.0, so if you are using a version after 0.20.0 you will get the AttributeError.

Example

Let’s look at an example where we want to select a subset of rows from a DataFrame. We will start with the dataset, which is a CSV file containing the names, charges and mass of four fundamental particles. We will save the dataset as particles.csv.

name,charge,mass
electron,-1, 0.511
muon,-1,105.7
tau,-1,1776.9
Z-boson,0,80433

Next, we will load the data into a DataFrame using pandas.

import pandas as pd

df = pd.read_csv('particles.csv')

subset = df.ix[[0,2],'name']

Let’s run the code to get the result:

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
Input In [3], in <cell line: 1>()
----> 1 subset = df.ix[[0,2],'name']

File ~/opt/anaconda3/lib/python3.8/site-packages/pandas/core/generic.py:5583, in NDFrame.__getattr__(self, name)
   5576 if (
   5577     name not in self._internal_names_set
   5578     and name not in self._metadata
   5579     and name not in self._accessors
   5580     and self._info_axis._can_hold_identifiers_and_holds_name(name)
   5581 ):
   5582     return self[name]
-> 5583 return object.__getattribute__(self, name)

AttributeError: 'DataFrame' object has no attribute 'ix'

We get an error because ix is a deprecated Pandas method.

Solution #1: Use loc() to Index DataFrame

To solve this error we can use the loc() method. The loc method provides access to a group of rows and columns by label(s) or a boolean array. Let’s look at the revised code:

import pandas as pd

df = pd.read_csv('particles.csv')

# Select appropriate indexes from the DataFrame index then use label indexing

subset = df.loc[df.index[[0, 2]], 'name']

print(subset)

Let’s run the code to get the result:

0    electron
2         tau
Name: name, dtype: object

We successfully retrieved the first and third rows of the name column.

Solution #2: Use iloc() to index DataFrame

We can also use the iloc() method to solve this error. The iloc method provides purely integer-location based indexing. To select rows of a specific column we need to provide a list of integers indicating positions and the integer location of the column using get_loc(). Let’s look at the revised code:

subset = df.iloc[[0,2], df.columns.get_loc('name')]

print(subset)

Let’s run the code to get the result:

0    electron
2         tau
Name: name, dtype: object

We can also select multiple columns by using the get_indexer() method, which returns the integer locations of the specified columns. Let’s look at the revised code:

# Get locations on the indexers and use positional indexing to select the rows

subset = df.iloc[[0,2], df.columns.get_indexer(['name', 'charge'])]

print(subset)
      name  charge
0  electron      -1
2       tau      -1

We successfully retrieved the first and third rows of the name and charge columns.

Summary

Congratulations on reading to the end of this tutorial! The method ix is deprecated as of pandas version 0.20.0. You can use DataFrame.loc or DataFrame.iloc instead.

For further reading on deprecated Pandas methods, go to the article:

To learn more about Python for data science and machine learning, go to the online courses page on Python for the most comprehensive courses available.

Have fun and happy researching!

Research Scientist at Moogsoft | + posts

Suf is a research scientist at Moogsoft, specializing in Natural Language Processing and Complex Networks. Previously he was a Postdoctoral Research Fellow in Data Science working on adaptations of cutting-edge physics analysis techniques to data-intensive problems in industry. In another life, he was an experimental particle physicist working on the ATLAS Experiment of the Large Hadron Collider. His passion is to share his experience as an academic moving into industry while continuing to pursue research. Find out more about the creator of the Research Scientist Pod here and sign up to the mailing list here!