Allow passing pathlib.PosixPath to the function read_from_text_file()

modmesh/track/dataframe.py

@@ -67,9 +67,11 @@ def read_from_text_file(
         :return: None
         """
 
-        if isinstance(fname, str):
+        if isinstance(fname, (str, os.PathLike)):
             if not os.path.exists(fname):
-                raise Exception("Text file '{}' does not exist".format(fname))
+                raise FileNotFoundError(
+                    "Text file '{}' does not exist".format(fname)
+                )
             fid = open(fname, 'rt')
             fid_ctx = contextlib.closing(fid)
         else:

tests/test_timeseries_dataframe.py

@@ -25,6 +25,9 @@
 # POSSIBILITY OF SUCH DAMAGE.
 
 import io
+import os
+import pathlib
+import tempfile
 import unittest
 
 import numpy as np
@@ -163,3 +166,45 @@ def test_dataframe_sort(self):
         col_data = reordered_tsdf['DELTA_VEL[1]']
         nd_arr = np.genfromtxt(io.StringIO(self.dlc_data), delimiter=',')[1:]
         self.assertEqual(list(col_data), list(nd_arr[:, 1]))
+
+    def test_read_from_text_file_accepts_str_path(self):
+        tsdf = dataframe.DataFrame()
+        with tempfile.NamedTemporaryFile(
+            mode='w', suffix='.csv', delete=False,
+        ) as fh:
+            fh.write(self.dlc_data)
+            path = fh.name
+        try:
+            tsdf.read_from_text_file(path)
+            self.assertEqual(tsdf._columns, self.col_sol)
+            self.assertEqual(tsdf._index_name, 'EPOCH')
+        finally:
+            os.unlink(path)
+
+# Theis test is for a bug reported in issue #786:
+# https://github.com/solvcon/modmesh/issues/786
+# Issue #786: If user uses time series dataframe under Linux,
+# it is likely to be given a `pathlib.PosixPath` instance to
+#  indicate the path to text file. This test is to make sure
+#  dataframe support a path which is from `pathlib`
+    def test_read_from_text_file_accepts_pathlib_path(self):
+        tsdf = dataframe.DataFrame()
+        with tempfile.NamedTemporaryFile(
+            mode='w', suffix='.csv', delete=False,
+        ) as fh:
+            fh.write(self.dlc_data)
+            path = pathlib.Path(fh.name)
+        try:
+            tsdf.read_from_text_file(path)
+            self.assertEqual(tsdf._columns, self.col_sol)
+            self.assertEqual(tsdf._index_name, 'EPOCH')
+        finally:
+            path.unlink()
+
+    def test_read_from_text_file_missing_raises_filenotfound(self):
+        tsdf = dataframe.DataFrame()
+        missing = pathlib.Path(tempfile.gettempdir()) / 'no_such_file.csv'
+        with self.assertRaises(FileNotFoundError):
+            tsdf.read_from_text_file(missing)
+
+# vim: set ff=unix fenc=utf8 et sw=4 ts=4 sts=4 tw=79: