code: def h2oassembly_download_mojo_col_op_string_properties_unary():
      test_unary_string_properties_function(
          H2OFrame.countmatches, pattern=["tt", "ex"]
      )
      test_unary_string_properties_function(H2OFrame.entropy)
      test_unary_string_properties_function(H2OFrame.nchar)
  
      path = os.path.join(
          os.getcwd(),
          "results",
          "h2oassembly_download_mojo_col_op_grep_words",
      )
      with open(path, "w") as text_file:
          text_file.writelines(
              [
                  "33ss33\n",
                  "sssss\n",
                  "tt\n",
                  "33ttaattaas\n",
                  "\n",
                  "asttatta\n",
                  "text\n",
              ]
          )
      test_unary_string_properties_function(
          H2OFrame.num_valid_substrings, path_to_words=path
      )
      test_unary_string_properties_function(
          H2OFrame.grep,
          pattern="tt",
          ignore_case=False,
          invert=False,
          output_logical=True,
      )
      test_unary_string_properties_function(
          H2OFrame.grep,
          pattern="tt",
          ignore_case=False,
          invert=True,
          output_logical=True,
      )
      test_unary_string_properties_function(
          H2OFrame.grep,
          pattern="tt",
          ignore_case=True,
          invert=False,
          output_logical=True,
      )
      test_unary_string_properties_function(
          H2OFrame.grep,
          pattern="tt",
          ignore_case=True,
          invert=True,
          output_logical=True,
      )
  
imports: import sys, os
  from tests import pyunit_utils
  from h2o.assembly import *
  from h2o.transforms.preprocessing import *
  from h2o.pipeline import H2OMojoPipeline
  import uuid
label_desc: Use image node_id 1 for calling a global function with example usage: h2oassembly_download_mojo_col_op_string_properties_unary() without return types