human
Write me a Python program to fix = (gray_hash(spec, hlen) if hashes else '') given the following:
I wrote the below code

    def get_arg(name, default=None):
        'Prefer    kwargs,    then    args,    then    default.'
        if (name in kwargs):
            return kwargs.get(name)
        elif (args is not None):
            return getattr(args, name, default)
        else:
            return default
    mode = get_arg('mode', 'short')
    hashes = get_arg('long', False)
    namespace = get_arg('namespace', False)
    flags = get_arg('show_flags', False)
    variants = get_arg('variants', False)
    hlen = 7
    if get_arg('very_long', False):
        hashes = True
        hlen = None
    nfmt = ('.' if namespace else '_')
    ffmt = ('$%+' if flags else '')
    vfmt = ('$+' if variants else '')
    format_string = ('$%s$@%s%s' % (nfmt, ffmt, vfmt))
    index = index_by(specs, ('architecture', 'compiler'))
    for (i, (architecture, compiler)) in enumerate(sorted(index)):
        if (i > 0):
            print()
        header = ('%s{%s}    /    %s{%s}' % (spack.spec.architecture_color, architecture, spack.spec.compiler_color, compiler))
        tty.hline(colorize(header), char='-')
        specs = index[(architecture, compiler)]
        specs.sort()
        abbreviated = [s.cformat(format_string) for s in specs]
        if (mode == 'paths'):
            width = max((len(s) for s in abbreviated))
            width += 2
            format = ('                %%-%ds%%s' % width)
            for (abbrv, spec) in zip(abbreviated, specs):
                prefix = (gray_hash(spec, hlen) if hashes else '')
                print((prefix + (format % (abbrv, spec.prefix))))
        elif (mode == 'deps'):
            for spec in specs:
                print(spec.tree(format=format_string, indent=4, prefix=((lambda s: gray_hash(s, hlen)) if hashes else None)))
        elif (mode == 'short'):
            if (not flags):
                def fmt(s):
                    string = ''
                    if hashes:
                        string += (gray_hash(s, hlen) + '    ')
                    string += s.cformat(('$-%s$@%s' % (nfmt,...

What's a good function header?
assistant
#Here is Python program to fix = (gray_hash(spec, hlen) if hashes else '')
.

def display_specs(specs, args=None, **kwargs):