diff --git a/Misc/ACKS b/Misc/ACKS index 3966ba67cc1..1db819477a0 100644 --- a/Misc/ACKS +++ b/Misc/ACKS @@ -820,6 +820,7 @@ Michael Muller Neil Muller Louis Munro R. David Murray +Matti Mäki Dale Nagata John Nagle Takahiro Nakayama diff --git a/Misc/NEWS b/Misc/NEWS index 1db58430197..76d4ad9b13b 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -49,6 +49,9 @@ Core and Builtins Library ------- +- Issue #14897: Enhance error messages of struct.pack and + struct.pack_into. Patch by Matti Mäki. + - Issue #12890: cgitb no longer prints spurious
tags in text mode when the logdir option is specified. diff --git a/Modules/_struct.c b/Modules/_struct.c index 0b20e26e6bf..0cd0512dcf5 100644 --- a/Modules/_struct.c +++ b/Modules/_struct.c @@ -1662,7 +1662,7 @@ s_pack(PyObject *self, PyObject *args) if (PyTuple_GET_SIZE(args) != soself->s_len) { PyErr_Format(StructError, - "pack requires exactly %zd arguments", soself->s_len); + "pack expected %zd items for packing (got %zd)", soself->s_len, PyTuple_GET_SIZE(args)); return NULL; } @@ -1701,9 +1701,19 @@ s_pack_into(PyObject *self, PyObject *args) assert(soself->s_codes != NULL); if (PyTuple_GET_SIZE(args) != (soself->s_len + 2)) { - PyErr_Format(StructError, - "pack_into requires exactly %zd arguments", - (soself->s_len + 2)); + if (PyTuple_GET_SIZE(args) == 0) { + PyErr_Format(StructError, + "pack_into expected buffer argument"); + } + else if (PyTuple_GET_SIZE(args) == 1) { + PyErr_Format(StructError, + "pack_into expected offset argument"); + } + else { + PyErr_Format(StructError, + "pack_into expected %zd items for packing (got %zd)", + soself->s_len, (PyTuple_GET_SIZE(args) - 2)); + } return NULL; }