Function _get_executable_info

lib/matplotlib/__init__.py:365–506

Get the version of some executable that Matplotlib optionally depends on. .. warning:: The list of executables that this function supports is set according to Matplotlib's internal needs, and may change without notice. Parameters ---------- name : str The

(name)

@functools.cache
def _get_executable_info(name):
    """
    Get the version of some executable that Matplotlib optionally depends on.

    .. warning::
       The list of executables that this function supports is set according to
       Matplotlib's internal needs, and may change without notice.

    Parameters
    ----------
    name : str
        The executable to query.  The following values are currently supported:
        "dvipng", "gs", "inkscape", "magick", "pdftocairo", "pdftops".  This
        list is subject to change without notice.

    Returns
    -------
    tuple
        A namedtuple with fields ``executable`` (`str`) and ``version``
        (`packaging.Version`, or ``None`` if the version cannot be determined).

    Raises
    ------
    ExecutableNotFoundError
        If the executable is not found or older than the oldest version
        supported by Matplotlib.  For debugging purposes, it is also
        possible to "hide" an executable from Matplotlib by adding it to the
        :envvar:`_MPLHIDEEXECUTABLES` environment variable (a comma-separated
        list), which must be set prior to any calls to this function.
    ValueError
        If the executable is not one that we know how to query.
    """

    def impl(args, regex, min_ver=None, ignore_exit_code=False):
        # Execute the subprocess specified by args; capture stdout and stderr.
        # Search for a regex match in the output; if the match succeeds, the
        # first group of the match is the version.
        # Return an _ExecInfo if the executable exists, and has a version of
        # at least min_ver (if set); else, raise ExecutableNotFoundError.
        try:
            output = subprocess.check_output(
                args, stderr=subprocess.STDOUT,
                text=True, errors="replace", timeout=30)
        except subprocess.CalledProcessError as _cpe:
            if ignore_exit_code:
                output = _cpe.output
            else:
                raise ExecutableNotFoundError(str(_cpe)) from _cpe
        except subprocess.TimeoutExpired as _te:
            msg = f"Timed out running {cbook._pformat_subprocess(args)}"
            raise ExecutableNotFoundError(msg) from _te
        except OSError as _ose:
            raise ExecutableNotFoundError(str(_ose)) from _ose
        match = re.search(regex, output)
        if match:
            raw_version = match.group(1)
            version = parse_version(raw_version)
            if min_ver is not None and version < parse_version(min_ver):