All 15 Command-Line Interfaces (argparse) questions
More in Command-Line Interfaces (argparse)
How do you create a basic command-line argument parser using argparse? What is the difference between a positional argument and an optional argument (flag) in argparse? How do you specify a default value and a type conversion for an argument? How do you restrict an argument's accepted values using the 'choices' parameter? How do you implement boolean flags using action='store_true' and action='store_false'? How do you provide a short and a long form for the same flag, like -v and --verbose? How do you implement subcommands (like 'git commit' or 'git push') using argparse's add_subparsers()? How do you group related arguments visually in the generated --help output using argument groups? How do you implement mutually exclusive arguments, where the user must choose EXACTLY ONE of a set of flags? How do you write a custom 'type=' validation function for argparse that raises a properly-formatted error for invalid input?
Advertisement
Python › Command-Line Interfaces (argparse)

How do you accept a variable number of arguments for a single flag, like a list of filenames?

Intermediate

Answer

Set 'nargs' to control how many values an argument consumes: '+' requires ONE OR MORE, '*' allows ZERO OR MORE, and a specific integer requires EXACTLY that many — the parsed result becomes a list instead of a single value.
parser.add_argument("--files", nargs="+", help="One or more input files")
args = parser.parse_args(["--files", "a.txt", "b.txt", "c.txt"])
print(args.files)  # ['a.txt', 'b.txt', 'c.txt']
Real-world example Accepting a list of input files to process in a batch CLI tool, like 'mytool --files a.txt b.txt c.txt'.

Common follow-ups: What's the difference in behavior between nargs='+' and nargs='*' when NO values are provided?

Data Types & Structures
All 15 Command-Line Interfaces (argparse) questions