python-poetry/poetry · error · ValueError

Expected one or two arguments (username, password), got {len

Error message

Expected one or two arguments (username, password), got {len(values)}

What it means

Raises ValueError in ConfigCommand.handle() when setting http-basic credentials with neither 1 nor 2 value arguments. With 1 value, Poetry treats it as username and prompts for the password interactively; with 2 values, it takes (username, password). Zero or 3+ values is invalid. The check at line 289-293 fires in the elif after the len==1 case.

Source

Thrown at src/poetry/console/commands/config.py:290

            from poetry.utils.password_manager import PasswordManager

            password_manager = PasswordManager(config)
            if self.option("unset"):
                if m.group(1) == "http-basic":
                    password_manager.delete_http_password(m.group(2))
                elif m.group(1) == "pypi-token":
                    password_manager.delete_pypi_token(m.group(2))

                return 0

            if m.group(1) == "http-basic":
                if len(values) == 1:
                    username = values[0]
                    # Only username, so we prompt for password
                    password = self.secret("Password:")
                    assert isinstance(password, str)
                elif len(values) != 2:
                    raise ValueError(
                        "Expected one or two arguments "
                        f"(username, password), got {len(values)}"
                    )
                else:
                    username = values[0]
                    password = values[1]

                password_manager.set_http_password(m.group(2), username, password)
            elif m.group(1) == "pypi-token":
                if len(values) != 1:
                    raise ValueError(
                        f"Expected only one argument (token), got {len(values)}"
                    )

                token = values[0]

                password_manager.set_pypi_token(m.group(2), token)

View on GitHub (pinned to 92b74dcfe3)

Solutions

1. Provide exactly 1 value (username, then you'll be prompted for password) or 2 values (username password): `poetry config http-basic.pypi myuser mypass`.
2. If you want the interactive prompt, pass just the username: `poetry config http-basic.pypi myuser`.

Example fix

# before (error)
poetry config http-basic.pypi myuser mypass extra
# after
poetry config http-basic.pypi myuser mypass

def validate_http_basic(values: list[str]) -> None:
    if len(values) not in (1, 2):
        raise ValueError(
            f"Expected 1 (username) or 2 (username, password) arguments, got {len(values)}"
        )

def is_valid_http_basic(values: list[str]) -> bool:
    return len(values) in (1, 2)

When it happens

Trigger: Running `poetry config http-basic.pypi` (zero values, which hits this path because the prohibited-settings check at line 167 only fires when no value is given AND key starts with 'http-basic' — but the value argument is multiple=True so empty list has falsy len). Or running with 3+ values like `poetry config http-basic.pypi user pass extra`.

Common situations: User omits both username and password expecting an interactive prompt that doesn't trigger (the 1-value prompt path requires exactly 1 arg), or passes extra stray arguments.

Related errors

• Expected only one argument (token), got {len(values)}
• You must pass the url. Example: poetry config repositories.f
• Expected a value for {setting_key} setting.
• You cannot remove the [repositories] section
• You can only specify one package when using the --extras opt

AI-assisted analysis of python-poetry/poetry@92b74dcfe3 (2026-08-04). Data as JSON: /data/errors/2f0bf87ff36a1576.json. Report an issue: GitHub.