strip invalid characters when parsing decimals

quiffen/core/transaction.py

@@ -388,18 +388,18 @@ def from_list(
                     current_split.memo = field_info
             elif line_code in {"$", "£"}:
                 if current_split:
-                    current_split.amount = Decimal(field_info.replace(",", ""))
+                    current_split.amount = utils.parse_decimal(field_info)
             elif line_code == "%":
                 if current_split:
-                    current_split.percent = Decimal(
-                        field_info.split(" ")[0].replace("%", "")
+                    current_split.percent = utils.parse_decimal(
+                        field_info.split(" ")[0]
                     )
             elif line_code in {"T", "U"}:
-                amount = field_info.replace(",", "")
+                amount = utils.parse_decimal(field_info)
                 if not splits:
                     kwargs["amount"] = amount
                 elif current_split:
-                    current_split.amount = Decimal(amount)
+                    current_split.amount = amount
             elif line_code == "M":
                 if not splits:
                     kwargs["memo"] = field_info
@@ -480,18 +480,20 @@ def from_list(
             kwargs["line_number"] = line_number
 
         # Set splits percentage if they don't already have one
-        total = Decimal(kwargs.get("amount", 0))
+        total = utils.parse_decimal(kwargs.get("amount", 0))
         if splits and total:
             for split in splits:
                 if split.percent is None and split.amount is not None:
-                    split.percent = Decimal(round(split.amount / total * 100, 2))
+                    split.percent = utils.parse_decimal(
+                        round(split.amount / total * 100, 2)
+                    )
                 # Check if the split percentage is correct
                 elif (
                     split.percent is not None
                     and split.amount is not None
                     and not (
-                        Decimal(round(split.percent, 2))
-                        == Decimal(
+                        utils.parse_decimal(round(split.percent, 2))
+                        == utils.parse_decimal(
                             round(
                                 split.amount / total * 100,
                                 2,

quiffen/utils.py

@@ -12,6 +12,9 @@
 ZERO_SEPARATED_DATE = re.compile(
     r"^(\d{2}|\d{4}|[a-zA-Z]+)0(\d{2}|[a-zA-Z]+)0(\d{2}|\d{4})$",
 )
+INVALID_AMOUNT_CHARACTERS = re.compile(
+    r"[^\d\.-]",
+)
 
 
 def parse_date(date_string: str, day_first: bool = False) -> datetime:
@@ -150,3 +153,10 @@ def apply_csv_formatting_to_container(
         }
     else:
         return apply_csv_formatting_to_scalar(obj, date_format)
+
+
+def parse_decimal(value: Union[str, Decimal]) -> Decimal:
+    """Parse a decimal from a string, removing non-numeric characters."""
+    if isinstance(value, Decimal):
+        return value
+    return Decimal(INVALID_AMOUNT_CHARACTERS.sub("", value))

tests/test_transaction.py

@@ -866,3 +866,21 @@ def test_check_number_allows_strings():
         check_number="Transfer",
     )
     assert transaction.check_number == "Transfer"
+
+
+def test_from_list_invalid_characters_in_amount_field():
+    """Test that the amount field correctly parses out invalid
+    characters (non-numeric).
+
+    Relates to issue #56.
+    https://github.com/isaacharrisholt/quiffen/issues/56
+    """
+    qif_list = [
+        "D2022-02-01",
+        "T$1,0ab£c00",
+        "L[Test To Account]",  # Brackets denote to account
+        "LTest Category 1",
+        "LTest Category 2",
+    ]
+    transaction, _ = Transaction.from_list(qif_list)
+    assert transaction.amount == 1000