Replace deprecated method in csv2rdf (#2901)

* Replace deprecated method

ConfigParser.readfp has been deprecated since Python 3.2 and is
removed in 3.12.

* Test that the config file is opened

rdflib/tools/csv2rdf.py

@@ -482,7 +482,7 @@ def main():
 
     if "-f" in opts:
         config = configparser.ConfigParser()
-        config.readfp(open(opts["-f"]))
+        config.read_file(open(opts["-f"]))
         for k, v in config.items("csv2rdf"):
             if k == "out":
                 csv2rdf.OUT = codecs.open(v, "w", "utf-8")

test/test_tools/test_csv2rdf.py

@@ -3,7 +3,9 @@
 import subprocess
 import sys
 from tempfile import mkstemp
+from unittest.mock import mock_open, patch, sentinel
 
+from rdflib.tools import csv2rdf
 from test.data import TEST_DATA_DIR
 
 REALESTATE_FILE_PATH = os.path.join(TEST_DATA_DIR, "csv", "realestate.csv")
@@ -44,3 +46,20 @@ def test_csv2rdf_cli_fileout(self):
             assert len(f.readlines()) == 228
         os.close(fh)
         os.remove(fname)
+
+    @patch.object(csv2rdf.CSV2RDF, "convert", return_value=None)
+    def test_csv2rdf_config_file_opened(self, config_mock):
+        """Test that the config file is read when specified."""
+        # Pretend there is a file with the section we're looking for.
+        # We don't care about the actual path, since it won't really be opened
+        # but when we try to open it, we will get back the section header
+        # so that the reader doesn't complain.
+        config_file = sentinel.file_path
+        open_mock = mock_open(read_data="[csv2rdf]")
+        # Also pretend that we're passing the arguments from the command line
+        cli_args = ["csv2rdf.py", "-f", config_file, str(REALESTATE_FILE_PATH)]
+        with patch.object(csv2rdf.sys, "argv", cli_args):
+            with patch("builtins.open", open_mock):
+                csv2rdf.main()
+                # Check that we've "opened" the right file
+                open_mock.assert_called_once_with(config_file)