How to use the rpy2.rinterface function in rpy2

def test_bool_NAComplex():
    with pytest.raises(ValueError):
        bool(ri.NA_Complex)

def test_getitem():
    vec = ri.StrSexpVector(['foo', 'bar', 'baz'])
    assert vec[1] == 'bar'
    with pytest.raises(TypeError):
        vec[(2, 3)]

def main():
    """Do the main work"""

    try:
		import rpy2
		import rpy2.rinterface
		rpy2.rinterface.set_initoptions((b'rpy2', b'--no-save',
										 b'--no-restore', b'--quiet'))
		import rpy2.robjects as robjects
		# rpy2 throws lots of warnings (that cannot be suppressed)
		# when packages are loaded
		warnings.filterwarnings("ignore")
		import rpy2.robjects.packages as rpackages
		from rpy2.robjects.vectors import StrVector
		import rpy2.robjects.numpy2ri
    except ImportError:
        grass.fatal(_("Cannot import rpy2 (https://rpy2.bitbucket.io)"
                      " library."
                      " Please install it (pip install rpy2)"
                      " or ensure that it is on path"
                      " (use PYTHONPATH variable)."))
    #Input variables
    network_map = options['input']

s += os.linesep
        version = self["version"]
        tmp = [n+': '+val[0] for n, val in itertools.izip(version.getnames(), version)]
        s += str.join(os.linesep, tmp)
        return s

    def __call__(self, string):
        p = self.parse(text=string)
        res = self.eval(p)
        return res

r = R()

globalEnv = conversion.ri2py(rinterface.globalEnv)
baseNameSpaceEnv = conversion.ri2py(rinterface.baseNameSpaceEnv)
emptyEnv = conversion.ri2py(rinterface.emptyEnv)

return(X_k)
        }
            ''')
        numpy2ri.deactivate()

        if True:
            numpy2ri.activate()
            rpy.r.assign('X', self.X)
            rpy.r.assign('Y', self.Y)
            rpy.r.assign('q', self.q)
            if self.forward_step:
                rpy.r('V = knockoff.filter(X, Y, fdr=q, knockoffs=knockoffs, stat=stat.forward_selection)$selected')
            elif self.sqrt_lasso:
                rinterface.set_writeconsole_regular(null_print)
                rpy.r('V = knockoff.filter(X, Y, fdr=q, knockoffs=knockoffs, stat=stat.sqrt_lasso)$selected')
                rinterface.set_writeconsole_regular(rinterface.consolePrint)
            else:
                rpy.r('V = knockoff.filter(X, Y, fdr=q, knockoffs=knockoffs)$selected')
            rpy.r('if (length(V) > 0) {V = V-1}')
            V = rpy.r('V')
            numpy2ri.deactivate()
            return np.asarray(V, np.int), np.asarray(V, np.int)
        else: # except:
            return [], []

'Only one R name should be associated with %s '
                    '(and we have %s)' % (rpyname, str(rnames))
                )
            rname = rnames[0]
            if rpyname in reserved_pynames:
                raise LibraryError('The symbol ' + rname +
                                   ' in the package "' + name + '"' +
                                   ' is conflicting with' +
                                   ' a Python object attribute')
            self._rpy2r[rpyname] = rname
            if (rpyname != rname) and (rname in self._exported_names):
                self._exported_names.remove(rname)
                self._exported_names.add(rpyname)
            try:
                riobj = self._env[rname]
            except rinterface.embedded.RRuntimeError as rre:
                warn(str(rre))
            rpyobj = conversion.rpy2py(riobj)
            if hasattr(rpyobj, '__rname__'):
                rpyobj.__rname__ = rname
            # TODO: shouldn't the original R name be also in the __dict__ ?
            self.__dict__[rpyname] = rpyobj

Returns the output to R's stdout() connection, 
        the value generated by evaluating the code, and a
        boolean indicating whether the return value would be
        visible if the line of code were evaluated in an R REPL.

        R Code evaluation and visibility determination are
        done via an R call of the form withVisible({<code>})

        '''
        old_writeconsole = ri.get_writeconsole()
        ri.set_writeconsole(self.write_console)
        try:
            res = ro.r("withVisible({%s\n})" % line)
            value = res[0]  # value (R object)
            visible = ro.conversion.ri2py(res[1])[0]  # visible (boolean)
        except (ri.RRuntimeError, ValueError) as exception:
            # otherwise next return seems to have copy of error
            warning_or_other_msg = self.flush()
            raise RInterpreterError(
                line, str_to_unicode(str(exception)), warning_or_other_msg)
        text_output = self.flush()
        ri.set_writeconsole(old_writeconsole)
        return text_output, value, visible
</code>

def rpy2py_basic(obj):    
    if hasattr(obj, '__len__'):
        if obj.typeof in [ri.INTSXP, ri.REALSXP, ri.CPLXSXP, 
                            ri.STRSXP]:
            res = [x for x in obj]
        elif obj.typeof in [ri.VECSXP]:
            res = [rpy2py(x) for x in obj]
        else:
            raise ValueError("Invalid type for 'obj'.")
    else:
        res = Robj(obj)
    return res
    #raise ValueError("Invalid type for 'obj'.")

def default_py2ri(o):
    """ Convert arbitrary Python object to :class:`rpy2.rinterface.Sexp` to objects,
    creating an R object with the content of the Python object in the process
    (wichi means data copying).

    :param o: object
    :rtype: :class:`rpy2.rinterface.Sexp` (and subclasses)

    """
    if isinstance(o, RObject):
        res = rinterface.Sexp(o)
    if isinstance(o, rinterface.Sexp):
        res = o
    elif isinstance(o, array.array):
        if o.typecode in ('h', 'H', 'i', 'I'):
            res = rinterface.SexpVector(o, rinterface.INTSXP)
        elif o.typecode in ('f', 'd'):
            res = rinterface.SexpVector(o, rinterface.REALSXP)
        else:
            raise(ValueError("Nothing can be done for this array type at the moment."))
    elif isinstance(o, bool):
        res = rinterface.SexpVector([o, ], rinterface.LGLSXP)
    elif isinstance(o, int):
        res = rinterface.SexpVector([o, ], rinterface.INTSXP)
    elif isinstance(o, float):
        res = rinterface.SexpVector([o, ], rinterface.REALSXP)
    elif isinstance(o, str):

def eval(self, line):
        '''
        Parse and evaluate a line with rpy2.
        Returns the output to R's stdout() connection
        and the value of eval(parse(line)).
        '''
        old_writeconsole = ri.get_writeconsole()
        ri.set_writeconsole(self.write_console)
        try:
            value = ri.baseenv['eval'](ri.parse(line))
        except (ri.RRuntimeError, ValueError) as exception:
            warning_or_other_msg = self.flush() # otherwise next return seems to have copy of error
            raise RInterpreterError(line, str_to_unicode(str(exception)), warning_or_other_msg)
        text_output = self.flush()
        ri.set_writeconsole(old_writeconsole)
        return text_output, value