How to print column names

In today’s post you will learn how to print column names from your dataframe in Pandas.

Listing the column names is one of the first things you do when you look at your data. It’s natural that you want to know the data structure, data size, data types in the beginning.

In case the table contains many columns, you are not able to print them, so you want to at least print their names.

You may think that printing column names is trivial. However, as you’ll see, printing column names isn’t easy at all, as you may run into a few problems that I’ll help you solve.

How to print column names

To list the column names, simply use a combination of the existing Pandas functions columns, values, and to_list.

This is my sample dataframe whose columns I would like to print out.

import pandas as pd

my_df = pd.DataFrame({'id':['id1','id2','id3'],
                          'Column1': ['2', '7', '6'],
                           'Column2': ['4', '5', '8'],
                           'Column3': ['4', '1', '9'],
                           'Column4': ['3', '3', '8'],
                      'Column5': ['2', '5', '4'],
                      'Column6': ['2', '7', '3']})

Use combinations of the column names listed above to get the column names.

import pandas as pd

my_df = pd.DataFrame({'id':['id1','id2','id3'],
                          'Column1': ['2', '7', '6'],
                           'Column2': ['4', '5', '8'],
                           'Column3': ['4', '1', '9'],
                           'Column4': ['3', '3', '8'],
                      'Column5': ['2', '5', '4'],
                      'Column6': ['2', '7', '3']})

columns = my_df.columns.values.tolist()

print(f"List of the columns: \n{columns}")

Pandas printed out the list of columns as I needed it.

How to solve column name printing problems

As I mentioned, the task is not easy, because it is easy to come across problems, i.e. AttributeError, which I pasted below.

Traceback (most recent call last):
  File "C:\Users\panda\PycharmProjects\venv\column_names.py", line 11, in 
    columns = pd.DataFrame.columns.values.tolist()
AttributeError: 'pandas._libs.properties.AxisProperty' object has no attribute 'values'

Process finished with exit code 1

The error occurred because I incorrectly called a combination of functions in Pandas.

columns = pd.DataFrame.columns.values.tolist()

As you can see, instead of referring to the dataframe, I called the columns function on the DataFrame function, which is incorrect.

The proper form is to call my_df.columns, and that’s the only way you should use it to avoid getting an AttributeError.

See also:
How to drop all columns except one in Pandas
How to one hot encode a column in PandasHow to select columns the Pandas way
How to fix KeyError(key) from err
How to print a full dataframe