In C++, it's an error to pass a string literal to a char* function
without a const_cast(). Rather than require every C++ extension
module to put a cast around string literals, fix the API to state the
const-ness.
I focused on parts of the API where people usually pass literals:
PyArg_ParseTuple() and friends, Py_BuildValue(), PyMethodDef, the type
slots, etc. Predictably, there were a large set of functions that
needed to be fixed as a result of these changes. The most pervasive
change was to make the keyword args list passed to
PyArg_ParseTupleAndKewords() to be a const char *kwlist[].
One cast was required as a result of the changes: A type object
mallocs the memory for its tp_doc slot and later frees it.
PyTypeObject says that tp_doc is const char *; but if the type was
created by type_new(), we know it is safe to cast to char *.
PyNumber_Check, rather than trying to convert to a float. Reimplemented
writer - now raises exceptions when it sees a quotechar but neither
doublequote or escapechar are set. Doublequote results are now more
consistent (eg, single quote should generate """", rather than "",
which is ambiguous).
when this limit is reached. Limit defaults to 128k, and is changed
by module set_field_limit() method. Previously, an unmatched quote
character could result in the entire file being read into the field
buffer, potentially exhausting virtual memory.
only contains instances of the dialect type, we can refer directly to the
dialect instances rather than creating new ones. In other words, if the
dialect comes from the registry, and we apply no further modifications,
the reader/writer can use the dialect object directly.
was done because we were previously performing validation of the dialect
from python, but this is now down within the C module. Also, the method
we were using to detect classes did not work with new-style classes.
