script.py

import pandas as pd

if __name__ == "__main__":
    no_observations = 4226
    ids = list(range(no_observations))

    out_observations = {"observation_id": ids, "class_id": [0] * no_observations}

    output_df = pd.DataFrame.from_dict(out_observations)

    output_df.to_csv("submission.csv", index=False)