How to Build a Data Helper Class in Python with OOP

class DataHelper:
    """A beginner-friendly OOP helper for handling simple datasets."""
    
    def __init__(self, filename):
        self.filename = filename
        self.data = self._load_data()
    
    def _load_data(self):
        """Load data from a CSV file into a list of dictionaries."""
        import csv
        with open(self.filename, 'r') as f:
            reader = csv.DictReader(f)
            return list(reader)
    
    def display_data(self):
        """Print all rows in a readable format."""
        for i, row in enumerate(self.data, 1):
            print(f"Record {i}: {row}")
    
    def filter_by_field(self, field, value):
        """Return rows where a field matches a specific value."""
        return [row for row in self.data if row.get(field) == value]
    
    def count_records(self):
        """Return the total number of records."""
        return len(self.data)


if __name__ == "__main__":
    import tempfile, os
    
    # Create a sample CSV file
    sample_content = "name,age,city\nAlice,25,New York\nBob,30,Chicago\nCharlie,22,New York\n"
    
    with tempfile.NamedTemporaryFile(mode='w', suffix='.csv', delete=False) as f:
        f.write(sample_content)
        temp_filename = f.name
    
    try:
        helper = DataHelper(temp_filename)
        print(f"Total records: {helper.count_records()}")
        print("\nAll data:")
        helper.display_data()
        print("\nFilter by city 'New York':")
        for row in helper.filter_by_field('city', 'New York'):
            print(row)
    finally:
        os.remove(temp_filename)