import json
import yaml

def load_yaml(filename):
    # Check file extension
    if not filename.lower().endswith(('.yaml', '.yml')):
        raise ValueError(f"File '{filename}' is not a YAML file")
    
    # Read file content
    with open(filename, 'r') as f:
        content = f.read()
        
    # Try to load as YAML
    try:
        data = yaml.safe_load(content)
        if not isinstance(data, dict):
            raise ValueError("YAML content does not contain a dictionary")
        return data
    except yaml.YAMLError as e:
        raise ValueError(f"Invalid YAML format in file '{filename}': {str(e)}")

#def main():
#    data = load_yaml(DATA)
#    json_data = json.dumps(data, indent=2)
#    print(json_data)

#if __name__ == "__main__":
#    main()