code: def test_gammainc_python():
      x1 = pt.dscalar()
      x2 = pt.dscalar()
      y = gammainc(x1, x2)
      test_func = function([x1, x2], y, mode=Mode("py"))
      assert np.isclose(test_func(1, 2), sp.gammainc(1, 2))
  
imports: import itertools
  import numpy
  import pytest
  import scipy.special
  import pytensor.tensor
  from pytensor import function
  from pytensor.compile.mode import Mode
  from pytensor.graph import ancestors
  from pytensor.graph.fg import FunctionGraph
  from pytensor.link.c.basic import CLinker
  from pytensor.scalar import ScalarLoop, float32, float64, int32
  from pytensor.scalar.math import betainc, betainc_grad, gammainc, gammaincc, gammal, gammau, hyp2f1
  from tests.link.test_link import make_function
label_desc: Use image node_id 1 for calling a global function with example usage: test_gammainc_python() without return types