pypa/pip · error · OptionError

Invalid value {string!r} for option {optname}; use 1/0, yes/

Error message

Invalid value {string!r} for option {optname}; use 1/0, yes/no, true/false, on/off

What it means

Pygments' get_bool_opt raises OptionError ('Invalid value ...') when the option value is a string that, after lowercasing, is not one of the recognized boolean literals (1/yes/true/on or 0/no/false/off). The type is acceptable (str) but the content is not a valid boolean spelling.

Source

Thrown at src/pip/_vendor/pygments/util.py:78

    The valid string values for ``True`` are ``1``, ``yes``, ``true`` and
    ``on``, the ones for ``False`` are ``0``, ``no``, ``false`` and ``off``
    (matched case-insensitively).
    """
    string = options.get(optname, default)
    if isinstance(string, bool):
        return string
    elif isinstance(string, int):
        return bool(string)
    elif not isinstance(string, str):
        raise OptionError(f'Invalid type {string!r} for option {optname}; use '
                          '1/0, yes/no, true/false, on/off')
    elif string.lower() in ('1', 'yes', 'true', 'on'):
        return True
    elif string.lower() in ('0', 'no', 'false', 'off'):
        return False
    else:
        raise OptionError(f'Invalid value {string!r} for option {optname}; use '
                          '1/0, yes/no, true/false, on/off')


def get_int_opt(options, optname, default=None):
    """As :func:`get_bool_opt`, but interpret the value as an integer."""
    string = options.get(optname, default)
    try:
        return int(string)
    except TypeError:
        raise OptionError(f'Invalid type {string!r} for option {optname}; you '
                          'must give an integer value')
    except ValueError:
        raise OptionError(f'Invalid value {string!r} for option {optname}; you '
                          'must give an integer value')

def get_list_opt(options, optname, default=None):
    """
    If the key `optname` from the dictionary `options` is a string,

View on GitHub (pinned to d7d0d0a394)

Solutions

Use exactly one of: 1, yes, true, on (true) or 0, no, false, off (false), case-insensitive.
Strip/normalize the string before it reaches get_bool_opt.
Map your application's boolean spellings to the accepted set before building the options dict.

Example fix

# before
opts['nowrap'] = 'enable'
val = get_bool_opt(opts, 'nowrap')

# after
opts['nowrap'] = 'on'
val = get_bool_opt(opts, 'nowrap')

Defensive patterns

Strategy: validation

Validate before calling

TRUE = {'1','yes','true','on'}
FALSE = {'0','no','false','off'}
raw = str(opts.get('nowrap','')).strip().lower()
if raw not in TRUE and raw not in FALSE:
    raise ValueError('nowrap must be a boolean literal')
get_bool_opt(opts, 'nowrap')

Type guard

def is_valid_bool_str(v: str) -> bool:
    return v.strip().lower() in {'1','yes','true','on','0','no','false','off'}

Try / catch

from pip._vendor.pygments.util import OptionError
try:
    val = get_bool_opt(opts, 'nowrap')
except OptionError:
    val = False

Prevention

Normalize boolean config strings to the accepted set before passing them on.
Document the accepted literals in your config schema.

When it happens

Trigger: Calling get_bool_opt with options[optname] set to a string like 'enable', 't', 'yep', or any non-recognized token; often from CLI flags or config files using a custom yes/no spelling.

Common situations: Config files using 'enable'/'disable' or 't'/'f'; localized values; trailing whitespace that wasn't stripped before validation.

Related errors

AI-assisted analysis of pypa/pip@d7d0d0a394 (2026-08-04). Data as JSON: /data/errors/fd7c1f3d2ca7035e.json. Report an issue: GitHub.