Command Line Arguments¶

When running as a script with python notebook.py, command-line arguments are available to your program in sys.argv, just like any other Python program. This means you can use argparse, simple-parsing, and other tools for specifying and parsing arguments.

You can also use tools like argparse when running as a notebook (marimo edit or marimo run) or exporting to HTML, IPYNB or another format (marimo export). In these cases, sys.argv is set to the notebook filename followed by any args following the -- separator.

For example, for

marimo edit notebook.py -- --lr 1e-4 --epochs 15

sets sys.argv to ["notebook.py", "--lr", "1e-4", "--epochs", "15"].

For usage examples, see the guide on running as a script.

Utility function for parsing arguments¶

marimo provides a utility function called mo.cli_args() for parsing arguments from strings into primitive data types (int, bool, float, str). However, unlike argparse and simple-parsing, this function does not let you declare your program's arguments, nor does it generate help text. For these reasons, we recommend using argparse or simple-parsing instead.

python notebook.py -- --arg1 value1 --arg2 value2
# mo.cli_args() == {'arg1': 'value1', 'arg2': 'value2'}

python notebook.py -- --arg1=10 --arg2=true --arg3
# mo.cli_args() == {'arg1': 10, 'arg2': True, 'arg3': ''}

python notebook.py -- --arg1 10.5 --arg2 hello --arg2 world
# mo.cli_args() == {'arg1': 10.5, 'arg2': ['hello', 'world']}

cli_args() -> CLIArgs

# Access the command line arguments
size = mo.cli_args().get("size") or 100

for i in range(size):
    print(i)