Apply suggestions from code review

Co-authored-by: Christoph Langer <[email protected]>

Author: NiklasRosenstein

pytr/main.py

@@ -194,7 +194,7 @@ def formatter(prog):
         "output",
         help="Output file path",
         metavar="OUTPUT",
-        type=argparse.FileType("w"),
+        type=argparse.FileType("w", encoding="utf8"),
         default="-",
         nargs="?",
     )

pytr/timeline.py

@@ -200,7 +200,7 @@ def finish_timeline_details(self, dl):
                 indent=2,
             )
 
-        with (dl.output_path / "account_transactions.csv").open("w") as f:
+        with (dl.output_path / "account_transactions.csv").open("w", encoding="utf8") as f:
             TransactionExporter().export(
                 f,
                 [Event.from_dict(ev) for ev in self.events_without_docs + self.events_with_docs],

pytr/transactions.py

@@ -129,7 +129,7 @@ def from_event(self, event: Event) -> Iterable[dict[str, Any]]:
             "isin": event.isin,
             "shares": self._decimal_format(event.shares, False),
             "fees": self._decimal_format(-event.fees) if event.fees is not None else None,
-            "taxes": self._decimal_format(-event.taxes),
+            "taxes": self._decimal_format(-event.taxes) if event.taxes is not None else None,
         }
 
         # Special case for saveback events. Example payload: https://github.com/pytr-org/pytr/issues/116#issuecomment-2377491990