How to use pandas to write a script for adding a new Column in a database?

 In the context of Python programming language, add a new Column “review_length” to your particular data frame review_df which can contain the length of each review in the review_text by using the following steps:-

Importing required libraries

You should try to ensure that you have pandas imported.

Loading or creating a data frame

Now you should try to load or create your particular dataframe.

Handling NaN values

You should replace the NaN values in the “review_text” with an empty string.

Calculating string length

Now you can use the str.len() method to calculate the length of each string.

Adding the length to a new Column

Now you should try to add the calculated lengths as a new Column in the dataframe.

Here is the coding implementation given of the above steps:-

Import pandas as pd

# Sample data to demonstrate the process

Data = {
    ‘review_id’: [1, 2, 3, 4, 5],
    ‘review_text’: [
        “Great product, really enjoyed using it!”,
        “Not what I expected. Quality could be better.”,
        None,
        “Decent value for money.”,
        “Will definitely recommend to friends and family!”
    ]
}
# Create DataFrame
Reviews_df = pd.DataFrame(data)
# Step 1: Print initial DataFrame to understand its structure
Print(“Initial DataFrame:
”, reviews_df)
# Step 2: Handle NaN values in ‘review_text’ column by replacing them with empty strings
Reviews_df[‘review_text’] = reviews_df[‘review_text’].fillna(‘’)
# Step 3: Calculate the length of each string in the ‘review_text’ column
# Use str.len() method to get the length of each review text
Reviews_df[‘review_length’] = reviews_df[‘review_text’].str.len()
# Step 4: Print the updated DataFrame to verify the new ‘review_length’ column
Print(“
Updated DataFrame with ‘review_length’:
”, reviews_df)

By following these above steps you can easily calculate and add the length of each review to your particular data frame, which would ensure the NaN values to handled appropriately.

Here is also a Java-based approach given how you can calculate the length of each review string, handling null values by considering their length as 0.

Import java.util.ArrayList;
Import java.util.List;
// Review class to store review text and its length
Class Review {
    Private String reviewText;
    Private int reviewLength;
    // Constructor
    Public Review(String reviewText) {
        This.reviewText = reviewText;
        This.reviewLength = calculateReviewLength(reviewText);
    }
    // Getter for review text
    Public String getReviewText() {
        Return reviewText;
    }
    // Getter for review length
    Public int getReviewLength() {
        Return reviewLength;
    }
    // Method to calculate the length of the review text
    Private int calculateReviewLength(String reviewText) {
        If (reviewText == null) {
            Return 0; // Treat null values as length 0
        }
        Return reviewText.length();
    }
    @Override
    Public String toString() {
        Return “Review{“ +
                “reviewText=’” + reviewText + ‘’’ +
                “, reviewLength=” + reviewLength +
                ‘}’;
    }
}
Public class ReviewLengthCalculator {
    Public static void main(String[] args) {
        // Sample list of reviews
        List reviews = new ArrayList<>();
        Reviews.add(“Great product, really enjoyed using it!”);
        Reviews.add(“Not what I expected. Quality could be better.”);
        Reviews.add(null);
        Reviews.add(“Decent value for money.”);
        Reviews.add(“Will definitely recommend to friends and family!”);
        // List to store Review objects
        List reviewList = new ArrayList<>();
        // Calculate the length of each review and store in Review objects
        For (String reviewText : reviews) {
            Review review = new Review(reviewText);
            reviewList.add(review);
        }
        // Print the list of Review objects to verify the lengths
        For (Review review : reviewList) {
            System.out.println(review);
        }
    }
}