code: def test_na_float():
      table = pa.table({"a": [1.0, None, 2.0]})
      df = table.__dataframe__()
      col = df.get_column_by_name("a")
      assert col.null_count == 1
      assert isinstance(col.null_count, int)
  
file_path: arrow/python/pyarrow/tests/interchange/test_interchange_spec.py
imports: import ctypes
  import hypothesis
  import hypothesis.strategies
  import numpy
  import pyarrow
  import pyarrow.tests.strategies
  import pytest
label_desc: Use image node_id 3 for calling a global function with example usage: test_na_float() without return types