How to Populate Data from a File into Class Objects in Python

Learn how to read data from a file and populate it into class objects, while avoiding common errors in Python coding.
---

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Populate data from file into class objects for each line then store it in a list

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
How to Populate Data from a File into Class Objects in Python

When working with data in Python, you may want to read information from a file and store it into objects for easy manipulation and access. However, you might run into some common pitfalls while attempting this. For instance, if you’re getting a NameError for variables that are not defined in your function, you're not alone. This guide will guide you through the process of efficiently populating class objects from a text file without running into errors.

Understanding the Problem

Initial Code Review

Here’s the initial code that caused the error:

[[See Video to Reveal this Text or Code Snippet]]

The main issue with the code above is that Sid, Sname, and Sage are not accessible within the for loop because they have not been defined in that scope.

The Solution

To fix the error and achieve your goal, follow these steps:

Read Each Line from the File: As you iterate over each line, you must split the line into its components (ID, Name, Age).

Create an Instance of the Class: Use the split data to instantiate a new Student object.

Append the Object to a List: Store each newly created object in a list.

Revised Code Example

Here’s how your corrected readStudent function should look:

[[See Video to Reveal this Text or Code Snippet]]

Explanation of the Changes

Object Creation: The Student object is then created using Student(Sid, Sname, Sage) which avoids any NameError since the variables are now defined in the proper scope.

Appending to List: We simply append the created student object without trying to split it again.

Conclusion

Reading data from files and populating class objects is a fundamental task in programming. By understanding scope and variable accessibility, you can avoid common pitfalls like NameError. With the corrected code above, you can smoothly read student data from your file, create objects, and store them in a list for future use.

Feel free to implement this approach in your projects, and watch how efficiently your data management improves! If you have further questions or encounter any issues, don't hesitate to reach out in the comments below.