owcsvimport: Fallback to float_precision="high" ...

... with non C-locale number format.

Orange/widgets/data/owcsvimport.py

@@ -1235,6 +1235,14 @@ def expand(ranges):
     if opts.group_separator != "":
         numbers_format_kwds["thousands"] = opts.group_separator
 
+    if numbers_format_kwds:
+        # float_precision = "round_trip" cannot handle non c-locale decimal and
+        # thousands sep (https://github.com/pandas-dev/pandas/issues/35365).
+        # Fallback to 'high'.
+        numbers_format_kwds["float_precision"] = "high"
+    else:
+        numbers_format_kwds["float_precision"] = "round_trip"
+
     with ExitStack() as stack:
         if isinstance(path, (str, bytes)):
             f = stack.enter_context(_open(path, 'rb'))
@@ -1253,7 +1261,6 @@ def expand(ranges):
             header=header, skiprows=skiprows,
             dtype=dtypes, parse_dates=parse_dates, prefix=prefix,
             na_values=na_values, keep_default_na=False,
-            float_precision="round_trip",
             **numbers_format_kwds
         )
         df = guess_types(df, dtypes, columns_ignored)

Orange/widgets/data/tests/test_owcsvimport.py

@@ -1,3 +1,4 @@
+# pylint: disable=no-self-use
 import unittest
 from unittest import mock
 from contextlib import ExitStack
@@ -287,6 +288,24 @@ class dialect(csv.excel):
         assert_array_equal(tb.X[:, 1], [0, np.nan, np.nan])
         assert_array_equal(tb.X[:, 2], [np.nan, 1, np.nan])
 
+    def test_decimal_format(self):
+        class Dialect(csv.excel):
+            delimiter = ";"
+
+        contents = b'3,21;3,37\n4,13;1.000,142'
+        opts = owcsvimport.Options(
+            encoding="ascii",
+            dialect=Dialect(),
+            decimal_separator=",",
+            group_separator=".",
+            columntypes=[
+                (range(0, 2), ColumnType.Numeric),
+            ],
+            rowspec=[],
+        )
+        df = owcsvimport.load_csv(io.BytesIO(contents), opts)
+        assert_array_equal(df.values, np.array([[3.21, 3.37], [4.13, 1000.142]]))
+
 
 if __name__ == "__main__":
     unittest.main()