Fix the typeerror ‘method’ object is not subscriptable in Python and Pandas?

Solve type error method not subscriptable in DataFrames

This exception occurs when using the bracket notation to call a Python (or one of its libraries – such as pandas for example) method. A subscriptable object is one that encapsulates other objects, such as a list, tuple or dictionary. Pandas DataFrame methods are not – hence the error.

Reproducing the problem

Assume you have the following DataFrame:

import pandas as pd

language = ['Java', 'Javascript', 'Java']
office = ['Los Angeles', 'New York', 'Paris']
salary = [116.0, 170.0, 82.0]
salaries = dict(office = office, language = language, salary = salary)
salaries_df = pd.DataFrame(data=salaries)
print (salaries_df)

This will return the following DataFrame rows:

	office	language	salary
0	Los Angeles	Java	116.0
1	New York	Javascript	170.0
2	Paris	Java	82.0

Let’s assume that we would like to drop one or more DataFrame columns – in this case the language column.

salaries_df.drop['language']

This will return the following exception

TypeError: 'method' object is not subscriptable

Here’s a screenshot from Jupyter – you will receive similar messages in VSCode, PyCharm, Spyder or other Python development environments.

Solving the problem

Luckily fixing this issue is simple. Just use parentheses instead of brackets:

salaries_df.drop('language')

Type not subscriptable in pandas Groupby

In a similar fashion you can encounter the same error on pandas Groupby objects. Let’s assume that we would like to obtain the average salary for each of the programming languages in our data set.

salaries_df.groupby['language'].mean()

This will throw a typeerror exception.

Solution, as we have seen before, is to use parentheses instead of brackets:

salaries_df.groupby('language').mean()

This will return the following DataFrame:

	salary
language
Java	99.0
Javascript	170.0