[FIXED] How can I solve this error (object of type 'float' has no len()), please?

Issue

I am working on the dataset AMAZON ALEXA REVIEW RATINGS

When I uploaded my dataset as below

df_alexa = pd.read_csv('amazon_alexa.tsv', sep='\t')

I wanted to add a new feature, which is called length, as shown below

df_alexa['length'] = df_alexa['verified_reviews'].apply(len)

But, I get the below, error:

TypeError: object of type 'float' has no len()

Any assistance, please?

Solution

I think that this output is caused of the fact that there are sometimes columns where the verified reviews is nan, so you have to calculate the length of the review, if it is a column with nan value it should return 0. So i've created a function to return 0 if it is an empty row. first i wanted to try it with a subset perhaps it would work but i didn't figure it out how to show lines with no reviews.

import pandas as pd

df = pd.read_csv('amazon_alexa.tsv', sep='\t')
df.dropna(subset=['verified_reviews'], inplace=True)

df['length'] = df['verified_reviews'].apply(len)

print(df)

Here beneath the code if there are empty rows and you want to see them.

import pandas as pd

def calculate_length(review):
    if pd.notna(review):
        return len(str(review))
    else:
        return 0

df = pd.read_csv('amazon_alexa.tsv', sep='\t')
df['length'] = df['verified_reviews'].apply(calculate_length)

print(df)

let me know if it worked and if not please comment

Answered By - Fridolin