Skip to content

bpo-39816: More descriptive error msg than "too many values to unpack" #19036

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
ZackerySpytz wants to merge 1 commit into from
Closed

bpo-39816: More descriptive error msg than "too many values to unpack" #19036

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
12 changes: 6 additions & 6 deletions Lib/test/test_unpack.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -62,28 +62,28 @@
>>> a, b = t
Traceback (most recent call last):
...
ValueError: too many values to unpack (expected 2)
ValueError: too many values to unpack (expected 2) from object of type 'tuple'

Unpacking tuple of wrong size
Unpacking list of wrong size

>>> a, b = l
Traceback (most recent call last):
...
ValueError: too many values to unpack (expected 2)
ValueError: too many values to unpack (expected 2) from object of type 'list'

Unpacking sequence too short

>>> a, b, c, d = Seq()
Traceback (most recent call last):
...
ValueError: not enough values to unpack (expected 4, got 3)
ValueError: not enough values to unpack (expected 4, got 3) from object of type 'Seq'

Unpacking sequence too long

>>> a, b = Seq()
Traceback (most recent call last):
...
ValueError: too many values to unpack (expected 2)
ValueError: too many values to unpack (expected 2) from object of type 'Seq'

Unpacking a sequence where the test for too long raises a different kind of
error
Expand Down Expand Up @@ -136,7 +136,7 @@
>>> () = [42]
Traceback (most recent call last):
...
ValueError: too many values to unpack (expected 0)
ValueError: too many values to unpack (expected 0) from object of type 'list'

"""

Expand Down
4 changes: 2 additions & 2 deletions Lib/test/test_unpack_ex.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -270,14 +270,14 @@
>>> a, *b, c, d, e = Seq()
Traceback (most recent call last):
...
ValueError: not enough values to unpack (expected at least 4, got 3)
ValueError: not enough values to unpack (expected at least 4, got 3) from object of type 'Seq'

Unpacking sequence too short and target appears last

>>> a, b, c, d, *e = Seq()
Traceback (most recent call last):
...
ValueError: not enough values to unpack (expected at least 4, got 3)
ValueError: not enough values to unpack (expected at least 4, got 3) from object of type 'Seq'

Unpacking a sequence where the test for too long raises a different kind of
error
Expand Down
21 changes: 13 additions & 8 deletions Python/ceval.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4387,14 +4387,17 @@ unpack_iterable(PyThreadState *tstate, PyObject *v,
if (argcntafter == -1) {
_PyErr_Format(tstate, PyExc_ValueError,
"not enough values to unpack "
"(expected %d, got %d)",
argcnt, i);
"(expected %d, got %d) from object of type "
"'%.200s'",
argcnt, i, Py_TYPE(v)->tp_name);
}
else {
_PyErr_Format(tstate, PyExc_ValueError,
"not enough values to unpack "
"(expected at least %d, got %d)",
argcnt + argcntafter, i);
"(expected at least %d, got %d) from "
"object of type '%.200s'",
argcnt + argcntafter, i,
Py_TYPE(v)->tp_name);
}
}
goto Error;
Expand All @@ -4413,8 +4416,9 @@ unpack_iterable(PyThreadState *tstate, PyObject *v,
}
Py_DECREF(w);
_PyErr_Format(tstate, PyExc_ValueError,
"too many values to unpack (expected %d)",
argcnt);
"too many values to unpack (expected %d) from object "
"of type '%.200s'",
argcnt, Py_TYPE(v)->tp_name);
goto Error;
}

Expand All @@ -4427,8 +4431,9 @@ unpack_iterable(PyThreadState *tstate, PyObject *v,
ll = PyList_GET_SIZE(l);
if (ll < argcntafter) {
_PyErr_Format(tstate, PyExc_ValueError,
"not enough values to unpack (expected at least %d, got %zd)",
argcnt + argcntafter, argcnt + ll);
"not enough values to unpack (expected at least %d, got %zd) "
"from object of type '%.200s'",
argcnt + argcntafter, argcnt + ll, Py_TYPE(v)->tp_name);
goto Error;
}

Expand Down