How to use the py.path.local.sysfind function in py

def test_vagrant(self, makegateway, tmpdir, monkeypatch):
        vagrant = py.path.local.sysfind("vagrant")
        if vagrant is None:
            pytest.skip("Vagrant binary not in PATH")
        monkeypatch.chdir(tmpdir)
        subprocess.check_call("vagrant init hashicorp/precise32", shell=True)
        subprocess.check_call("vagrant up --provider virtualbox", shell=True)
        gw = makegateway("vagrant_ssh=default")
        rinfo = gw._rinfo()
        rinfo.cwd == "/home/vagrant"
        rinfo.executable == "/usr/bin/python"
        subprocess.check_call("vagrant halt", shell=True)

def test_create_crontab_empty(tmpdir, monkeypatch):
    def sysexec_raise(x, y):
        raise py.process.cmdexec.Error(1, 2, x, "", "")

    monkeypatch.setattr(py.path.local, "sysexec", sysexec_raise)
    tw = py.io.TerminalWriter()
    path = tmpdir.join("devpi-ctl")
    if py.path.local.sysfind("crontab"):
        cron = gendeploy.create_crontab(tw, tmpdir, path)
        assert cron
        expect = "crontab %s" % tmpdir.join("crontab")
        assert expect in cron
        assert "@reboot" in tmpdir.join("crontab").read()
    else:
        pytest.skip('crontab not installed')

def test_sysfind_in_currentdir(self, path1):
        cmd = py.path.local.sysfind('cmd')
        root = cmd.new(dirname='', basename='') # c:\ in most installations
        with root.as_cwd():
            x = py.path.local.sysfind(cmd.relto(root))
            assert x.check(file=1)

def test_create_crontab(tmpdir, monkeypatch):
    monkeypatch.setattr(py.path.local, "sysexec", lambda x, y: "")
    tw = py.io.TerminalWriter()
    path = tmpdir.join("devpi-ctl")
    if py.path.local.sysfind("crontab"):
        cron = gendeploy.create_crontab(tw, tmpdir, path)
        assert cron
        expect = "crontab %s" % tmpdir.join("crontab")
        assert expect in cron
        assert "@reboot" in tmpdir.join("crontab").read()
    else:
        pytest.skip('crontab not installed')

def getexecutable(name, cache={}):
    try:
        return cache[name]
    except KeyError:
        executable = py.path.local.sysfind(name)
        if executable:
            import subprocess

            popen = subprocess.Popen(
                [str(executable), "--version"],
                universal_newlines=True,
                stderr=subprocess.PIPE,
            )
            out, err = popen.communicate()
            if name == "jython":
                if not err or "2.5" not in err:
                    executable = None
                if "2.5.2" in err:
                    executable = None  # http://bugs.jython.org/issue1790
            elif popen.returncode != 0:
                # handle pyenv's 127

def setup_module(mod):
    py.test.importorskip("docutils")
    if not py.path.local.sysfind("gs") or \
           not py.path.local.sysfind("dot") or \
           not py.path.local.sysfind("latex"):
        py.test.skip("ghostscript, graphviz and latex needed")
    mod.datadir = getdata()

def popen_output(self, args, cwd=None, report=True):
        if isinstance(args, str):
            args = shlex.split(args)
        assert args[0], args
        args = [str(x) for x in args]
        if cwd == None:
            cwd = self.cwd
        cmd = py.path.local.sysfind(args[0])
        if not cmd:
            self.fatal("command not found: %s" % args[0])
        args[0] = str(cmd)
        if report:
            self.report_popen(args, cwd)
        return subprocess.check_output(args, cwd=str(cwd)).decode('utf-8')

def which(program, path):
    """Finds the full path to an executable."""
    full_path = None

    if path:
        full_path = py.path.local.sysfind(program, paths=[path])

    if full_path:
        return full_path.strpath

    full_path = py.path.local.sysfind(program)

    if full_path:
        return full_path.strpath

    logger.error("Program {} not found.".format(program))
    raise CommandFailed("Program {} not found".format(program))

def _cmake_needed():
    """Determine if a ``cmake`` binary is needed.

    This will check if ``cmake`` is on the path so it can be used if needed.
    Installing ``cmake`` into the ``nox``-managed virtual environment can be
    forced by setting the ``NOX_INSTALL_CMAKE`` environment variable.
    """
    if "NOX_INSTALL_CMAKE" in os.environ:
        return True

    return py.path.local.sysfind("cmake") is None

def _check_helper(cls, helper):
        if py.path.local.sysfind(helper) is None:
            py.test.skip("%s is not on your path." % helper)
        else:
            return helper
    _check_helper = classmethod(_check_helper)