Pandas DataFrame Append Error: 'DataFrame' object has no attribute 'append'

The error "'DataFrame' object has no attribute 'append'" typically arises because your current pandas version might not support the append method for adding rows to a DataFrame. This article provides solutions using the concat and loc methods.

Understanding the Issue

The append method was traditionally used to add rows to a DataFrame. However, in newer pandas versions, the append method has been deprecated for performance and efficiency reasons. Instead, it's recommended to use the concat or loc methods.

Solutions

1. Using the concat Method

The concat method is the preferred way to append rows to a DataFrame. It efficiently combines DataFrames along an axis (rows or columns). Here's how to use it:

import pandas as pd

concentration_list = ['saline0.05%', 'saline0.10%', 'saline0.20%', 'saline0.30%', 'saline0.40%','saline0.50%']
df_saline_median = pd.DataFrame(columns=['1kHz_mag','2kHz_mag','3kHz_mag','7kHz_mag','11kHz_mag','17kHz_mag',
                                         '23kHz_mag','31kHz_mag','43kHz_mag','61kHz_mag','89kHz_mag','127kHz_mag',
                                         '179kHz_mag','251kHz_mag','349kHz_mag'])

for i in concentration_list:
    saline_group = df[df['name'] == i]
    df_saline_median = pd.concat([df_saline_median, saline_group.median()], ignore_index=True)

df_saline_median

2. Using the loc Method

The loc method allows you to access and modify rows in a DataFrame by their label or integer position. You can use it to append a row by selecting the last row's index and assigning the new data:

import pandas as pd

concentration_list = ['saline0.05%', 'saline0.10%', 'saline0.20%', 'saline0.30%', 'saline0.40%','saline0.50%']
df_saline_median = pd.DataFrame(columns=['1kHz_mag','2kHz_mag','3kHz_mag','7kHz_mag','11kHz_mag','17kHz_mag',
                                         '23kHz_mag','31kHz_mag','43kHz_mag','61kHz_mag','89kHz_mag','127kHz_mag',
                                         '179kHz_mag','251kHz_mag','349kHz_mag'])

for i in concentration_list:
    saline_group = df[df['name'] == i]
    df_saline_median.loc[len(df_saline_median)] = saline_group.median()

df_saline_median

Choosing the Right Approach

• The concat method is more efficient for appending large amounts of data, especially when working with multiple DataFrames.
• The loc method is useful for appending single rows or small sets of data.

By understanding the reasons behind the error and implementing these alternative methods, you can efficiently add rows to your Pandas DataFrame and avoid encountering the "'DataFrame' object has no attribute 'append'" error.