[mankind806]

Describe the bug

MT535_Miniparser.parse does not reset total_value for each holding. A holding without a :19A::HOLD// clause gets the total value of the holding before it in the same message. If the first holding in the message has no :19A: clause, parse raises UnboundLocalError, so get_holdings() fails.

Cause

fints/utils.py at v5.0.1 (and at master eda20b4):

• line 165: isin, name, market_price, price_symbol, price_date, pieces, acquisitionprice = (None,)*7 resets seven of the eight values of a holding. total_value is not among them.
• lines 191-193: total_value is assigned only if a :19A::HOLD//... clause matches.
• line 205: Holding(..., total_value=total_value, ...) always reads it. For the second and later holdings that is the value from the previous loop pass; for the first holding it is a name that was never assigned.

get_holdings (fints/client.py:704-714) creates one MT535_Miniparser per HIWPD segment and calls parse on its lines, so the carry-over runs across all holdings of one segment.

Impact

• A holding without :19A: is reported with a plausible but wrong total value (the one of its neighbour) and no warning. A caller that sums the depot value or stores it gets a wrong number.
• If the first holding has no :19A:, get_holdings() raises UnboundLocalError: cannot access local variable 'total_value' and no holding is returned.

I did not show that a particular bank omits :19A:. The parser treats the clause as optional (it only matches it if present), so the missing case should be handled either way.

Affected versions

python-fints 5.0.1 (tag v5.0.1, commit eda20b4fec2e612dc7942234884be2e8c4fe632f) and master at the same commit (checked 2026-11-09; fints/utils.py is identical in both). Older versions were not tested.

Reproduction

No network, synthetic data. Python 3.14.8, python-fints 5.0.1 from PyPI.

from fints.utils import MT535_Miniparser


def fin(isin, name, pieces, value=None):
    lines = [":16R:FIN", f":35B:ISIN {isin}|/DE/X1|{name}",
             ":90B::MRKT//ACTU/EUR10,00", ":98A::PRIC//20260101",
             f":93B::AGGR//UNIT/{pieces},"]
    if value is not None:
        lines.append(f":19A::HOLD//EUR{value}")
    lines.append(":16S:FIN")
    return lines


def parse(*holdings):
    lines = [l for h in holdings for l in h] + ["-"]  # an MT535 ends with a "-" line
    return MT535_Miniparser().parse(lines)


# A: the second holding has no :19A:
for h in parse(fin("AA0000000001", "ONE", "5", "50,00"), fin("AA0000000002", "TWO", "7")):
    print("A", h.name, h.pieces, h.total_value)

# B: the first holding has no :19A:
try:
    parse(fin("AA0000000003", "THREE", "1"))
except Exception as e:
    print("B", type(e).__name__, e)

Actual output:

A ONE 5.0 50.0
A TWO 7.0 50.0
B UnboundLocalError cannot access local variable 'total_value' where it is not associated with a value

Expected: A TWO 7.0 None, and for B a holding with total_value=None.

Not checked

• No real bank and no real MT535 message; whether banks omit :19A: for some holdings (or in which cases) is not known to me. The SWIFT/DK message definition was not read for this report.
• Only total_value was examined; the other seven values are reset in line 165.
• Python versions other than 3.14.8, and versions before 5.0.1.
• The full test suite was not run (pytest was not available in my environment); the two new tests were run as plain function calls.

Solution

One line (fints/utils.py:165) and two tests (new file tests/test_mt535.py). The patch is against eda20b4 (= v5.0.1 = master on 2026-11-09). The new tests fail before the change (case B with UnboundLocalError, case A with the wrong value 50.0) and pass after it.

diff --git a/fints/utils.py b/fints/utils.py
index f02edb6..a656131 100644
--- a/fints/utils.py
+++ b/fints/utils.py
@@ -162,7 +162,7 @@ class MT535_Miniparser:
         finsegs = self.grab_financial_instrument_segments(clauses)
         # Third: Extract financial instrument data
         for finseg in finsegs:
-            isin, name, market_price, price_symbol, price_date, pieces, acquisitionprice = (None,)*7
+            isin, name, market_price, price_symbol, price_date, pieces, total_value, acquisitionprice = (None,)*8
             for clause in finseg:
                 # identification of instrument
                 # e.g. ':35B:ISIN LU0635178014|/DE/ETF127|COMS.-MSCI EM.M.T.U.ETF I'
diff --git a/tests/test_mt535.py b/tests/test_mt535.py
new file mode 100644
index 0000000..69b3b49
--- /dev/null
+++ b/tests/test_mt535.py
@@ -0,0 +1,34 @@
+from fints.utils import MT535_Miniparser
+
+
+def _mt535_holding(isin, name, pieces, total_value=None):
+    lines = [
+        ":16R:FIN",
+        ":35B:ISIN {}|/DE/X1|{}".format(isin, name),
+        ":90B::MRKT//ACTU/EUR10,00",
+        ":98A::PRIC//20260101",
+        ":93B::AGGR//UNIT/{},".format(pieces),
+    ]
+    if total_value is not None:
+        lines.append(":19A::HOLD//EUR{}".format(total_value))
+    lines.append(":16S:FIN")
+    return lines
+
+
+def test_mt535_holding_without_total_value_does_not_inherit_previous():
+    lines = _mt535_holding("AA0000000001", "ONE", "5", "50,00")
+    lines += _mt535_holding("AA0000000002", "TWO", "7")
+    lines.append("-")
+
+    first, second = MT535_Miniparser().parse(lines)
+
+    assert first.total_value == 50.0
+    assert second.total_value is None
+
+
+def test_mt535_first_holding_without_total_value():
+    lines = _mt535_holding("AA0000000003", "THREE", "1") + ["-"]
+
+    (holding,) = MT535_Miniparser().parse(lines)
+
+    assert holding.total_value is None

AI disclosure

An AI assistant (Claude, Anthropic) helped find and write this report and the patch. The reproduction and the two tests were run on python-fints 5.0.1, and the cause was checked against the source by a second review step. The account owner allows AI-prepared bug-fix submissions; questions are welcome and will be answered.