The Pandas method as_matrix is deprecated as of version 0.23.0. If you want to convert a DataFrame to its NumPy array representation, you can use DataFrame.values() or DataFrame.to_numpy.
This tutorial will go through how to solve this error with code examples.
Table of contents
AttributeError: ‘DataFrame’ object has no attribute ‘as_matrix’
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 ‘as_matrix‘ tells us that the DataFrame object we are handling does not have the as_matrix as an attribute. The as_matrix() method is deprecated as of version 0.23.0, so if you are using a version after 0.23.0 you will get the AttributeError.
Example
Let’s look at an example where we want to convert a DataFrame to a NumPy array. We will start with a CSV file containing pizza names and prices. We will save the file as pizzas.csv.
pizza,price margherita,£7.99 pepperoni,£8.99 four cheeses,£10.99 funghi,£8.99
Next, we will load the data into a DataFrame using pandas.
import pandas as pd
df = pd.read_csv('pizzas.csv')
print(df)
pizza price 0 margherita £7.99 1 pepperoni £8.99 2 four cheeses £10.99 3 funghi £8.99
We want the pizza prices to be floating-point numbers instead of strings. We will use the string accessor method to remove the £ character and then cast the column to float using astype().
df.price = df.price.str.replace('£','').astype(float)
print(df.price)
0 7.99 1 8.99 2 10.99 3 8.99 Name: price, dtype: float64
Then we will try to convert the DataFrame to a NumPy array using as_matrix.
arr = df.as_matrix() print(arr)
---------------------------------------------------------------------------
AttributeError Traceback (most recent call last)
Input In [23], in <cell line: 1>()
----> 1 arr = df.as_matrix()
2 print(arr)
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 'as_matrix'
The error occurs because as_matrix() is a deprecated method.
Solution
To solve this error we can either use DataFrame.values or DataFrame.to_numpy(). Let’s look at how to convert the DataFrame to a NumPy array using values:
arr = df.values print(arr) print(type(arr))
Let’s run the code to get the result.
[['margherita' 7.99] ['pepperoni' 8.99] ['four cheeses' 10.99] ['funghi' 8.99]] <class 'numpy.ndarray'>
Let’s look at how to convert a DataFrame to a NumPy array using to_numpy().
arr = df.to_numpy() print(arr) print(type(arr))
Let’s run the code to see the result:
[['margherita' 7.99] ['pepperoni' 8.99] ['four cheeses' 10.99] ['funghi' 8.99]] <class 'numpy.ndarray'>
Summary
Congratulations on reading to the end of this tutorial! The method as_matrix is deprecated as of pandas version 0.23.0. You can use DataFrame.values or DataFrame.to_numpy instead.
For further reading on deprecated Pandas methods, go to the article:
- How to Solve Python AttributeError: ‘DataFrame’ object has no attribute ‘ix’
- How to Solve Python AttributeError: module ‘pandas’ has no attribute ‘rolling_mean’
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