Replace invalid characters in string decoding (#4)

* Replace invalid characters in string decoding

* Add test

* Add changelog entry

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### Changed
 - When `EdfSignal.physical_min` or `EdfSignal.physical_max` do not fit into their header fields, they are now always rounded down or up, respectively, to ensure all physical values lie within the physical range ([#2](https://github.com/the-siesta-group/edfio/pull/2)).
+- Support non-standard header fields (not encoded as UTF-8) by replacing incompatible characters with "�" ([#4](https://github.com/the-siesta-group/edfio/pull/4)).
 
 
 ## [0.1.0] - 2023-11-09

edfio/_header_field.py

@@ -21,7 +21,7 @@ def encode_str(value: str, length: int) -> bytes:
 
 
 def decode_str(field: bytes) -> str:
-    return field.decode().rstrip()
+    return field.decode(errors="replace").rstrip()
 
 
 def encode_int(value: int, length: int) -> bytes:

tests/test_header_field.py

@@ -3,6 +3,7 @@
 from edfio._header_field import (
     RawHeaderFieldDate,
     decode_float,
+    decode_str,
     encode_float,
     encode_int,
 )
@@ -30,6 +31,11 @@ def test_encode_float(value: float, expected: bytes):
     assert encode_float(value, 8) == expected
 
 
+def test_decode_str():
+    assert decode_str("è".encode("latin-1")) == "�"
+    assert decode_str("è".encode()) == "è"
+
+
 @pytest.mark.parametrize("field", [b"1E2345  ", b"-1E2345 "])
 def test_decode_float_exceeding_float_range_fails(field: bytes):
     with pytest.raises(ValueError, match="outside float range"):