"""Count the penguins in each species.

Run from a terminal:
    python3 penguin_count.py ../data/penguins.csv
"""
import argparse

import pandas as pd


def count_species(csv_path):
    """Read a CSV file and count each penguin species."""
    df = pd.read_csv(csv_path)
    return df["species"].value_counts()


def main():
    # argparse reads the file path from the terminal command.
    parser = argparse.ArgumentParser(description="Count penguins per species")
    parser.add_argument("csvfile", help="path to the penguins CSV")
    args = parser.parse_args()

    print(count_species(args.csvfile).to_string())


# Run main() when we execute this file, but not when we import it.
if __name__ == "__main__":
    main()