new CSV file processing module - see PEP 305

1 files changed, 1465 insertions, 0 deletions

diff --git a/Modules/_csv.c b/Modules/_csv.c
new file mode 100644
index 0000000..701904a
--- /dev/null
+++ b/Modules/_csv.c
@@ -0,0 +1,1465 @@
+/* TODO:
+*/
+
+#include "Python.h"
+#include "structmember.h"
+
+/* begin 2.2 compatibility macros */
+#ifndef PyDoc_STRVAR
+/* Define macros for inline documentation. */
+#define PyDoc_VAR(name) static char name[]
+#define PyDoc_STRVAR(name,str) PyDoc_VAR(name) = PyDoc_STR(str)
+#ifdef WITH_DOC_STRINGS
+#define PyDoc_STR(str) str
+#else
+#define PyDoc_STR(str) ""
+#endif
+#endif /* ifndef PyDoc_STRVAR */
+
+#ifndef PyMODINIT_FUNC
+#	if defined(__cplusplus)
+#		define PyMODINIT_FUNC extern "C" void
+#	else /* __cplusplus */
+#		define PyMODINIT_FUNC void
+#	endif /* __cplusplus */
+#endif
+/* end 2.2 compatibility macros */
+
+static PyObject *error_obj;	/* CSV exception */
+static PyObject *dialects;      /* Dialect registry */
+
+typedef enum {
+	START_RECORD, START_FIELD, ESCAPED_CHAR, IN_FIELD, 
+	IN_QUOTED_FIELD, ESCAPE_IN_QUOTED_FIELD, QUOTE_IN_QUOTED_FIELD
+} ParserState;
+
+typedef enum {
+	QUOTE_MINIMAL, QUOTE_ALL, QUOTE_NONNUMERIC, QUOTE_NONE
+} QuoteStyle;
+
+typedef struct {
+	QuoteStyle style;
+	char *name;
+} StyleDesc;
+
+static StyleDesc quote_styles[] = {
+	{ QUOTE_MINIMAL,    "QUOTE_MINIMAL" },
+	{ QUOTE_ALL,        "QUOTE_ALL" },
+	{ QUOTE_NONNUMERIC, "QUOTE_NONNUMERIC" },
+	{ QUOTE_NONE,       "QUOTE_NONE" },
+	{ 0 }
+};
+
+typedef struct {
+        PyObject_HEAD
+        
+	int doublequote;	/* is " represented by ""? */
+	char delimiter;		/* field separator */
+	char quotechar;		/* quote character */
+	char escapechar;	/* escape character */
+	int skipinitialspace;	/* ignore spaces following delimiter? */
+	PyObject *lineterminator; /* string to write between records */
+	QuoteStyle quoting;	/* style of quoting to write */
+
+	int strict;		/* raise exception on bad CSV */
+} DialectObj;
+
+staticforward PyTypeObject Dialect_Type;
+
+typedef struct {
+        PyObject_HEAD
+
+        PyObject *input_iter;   /* iterate over this for input lines */
+
+        DialectObj *dialect;    /* parsing dialect */
+
+	PyObject *fields;	/* field list for current record */
+	ParserState state;	/* current CSV parse state */
+	char *field;		/* build current field in here */
+	int field_size;		/* size of allocated buffer */
+	int field_len;		/* length of current field */
+	int had_parse_error;	/* did we have a parse error? */
+} ReaderObj;
+
+staticforward PyTypeObject Reader_Type;
+
+#define ReaderObject_Check(v)   ((v)->ob_type == &Reader_Type)
+
+typedef struct {
+        PyObject_HEAD
+
+        PyObject *writeline;    /* write output lines to this file */
+
+        DialectObj *dialect;    /* parsing dialect */
+
+	char *rec;		/* buffer for parser.join */
+	int rec_size;		/* size of allocated record */
+	int rec_len;		/* length of record */
+	int num_fields;		/* number of fields in record */
+} WriterObj;        
+
+staticforward PyTypeObject Writer_Type;
+
+/*
+ * DIALECT class
+ */
+
+static PyObject *
+get_dialect_from_registry(PyObject * name_obj)
+{
+        PyObject *dialect_obj;
+
+        dialect_obj = PyDict_GetItem(dialects, name_obj);
+        if (dialect_obj == NULL)
+            return PyErr_Format(error_obj, "unknown dialect");
+        Py_INCREF(dialect_obj);
+        return dialect_obj;
+}
+
+static int
+check_delattr(PyObject *v)
+{
+	if (v == NULL) {
+		PyErr_SetString(PyExc_TypeError, 
+                                "Cannot delete attribute");
+		return -1;
+        }
+        return 0;
+}
+
+static PyObject *
+get_string(PyObject *str)
+{
+        Py_XINCREF(str);
+        return str;
+}
+
+static int
+set_string(PyObject **str, PyObject *v)
+{
+        if (check_delattr(v) < 0)
+                return -1;
+        if (!PyString_Check(v) && !PyUnicode_Check(v)) {
+                PyErr_BadArgument();
+                return -1;
+        }
+        Py_XDECREF(*str);
+        Py_INCREF(v);
+        *str = v;
+        return 0;
+}
+
+static PyObject *
+get_nullchar_as_None(char c)
+{
+        if (c == '\0') {
+                Py_INCREF(Py_None);
+                return Py_None;
+        }
+        else
+                return PyString_FromStringAndSize((char*)&c, 1);
+}
+
+static int
+set_None_as_nullchar(char * addr, PyObject *v)
+{
+        if (check_delattr(v) < 0)
+                return -1;
+        if (v == Py_None)
+                *addr = '\0';
+        else if (!PyString_Check(v) || PyString_Size(v) != 1) {
+                PyErr_BadArgument();
+                return -1;
+        }
+        else
+             *addr = PyString_AsString(v)[0];
+        return 0;
+}
+
+static PyObject *
+Dialect_get_lineterminator(DialectObj *self)
+{
+        return get_string(self->lineterminator);
+}
+
+static int
+Dialect_set_lineterminator(DialectObj *self, PyObject *value)
+{
+        return set_string(&self->lineterminator, value);
+}
+
+static PyObject *
+Dialect_get_escapechar(DialectObj *self)
+{
+        return get_nullchar_as_None(self->escapechar);
+}
+
+static int
+Dialect_set_escapechar(DialectObj *self, PyObject *value)
+{
+        return set_None_as_nullchar(&self->escapechar, value);
+}
+
+static PyObject *
+Dialect_get_quoting(DialectObj *self)
+{
+        return PyInt_FromLong(self->quoting);
+}
+
+static int
+Dialect_set_quoting(DialectObj *self, PyObject *v)
+{
+        int quoting;
+        StyleDesc *qs = quote_styles;
+
+        if (check_delattr(v) < 0)
+                return -1;
+        if (!PyInt_Check(v)) {
+                PyErr_BadArgument();
+                return -1;
+        }
+        quoting = PyInt_AsLong(v);
+	for (qs = quote_styles; qs->name; qs++) {
+		if (qs->style == quoting) {
+                        self->quoting = quoting;
+                        return 0;
+                }
+        }
+        PyErr_BadArgument();
+        return -1;
+}
+
+static struct PyMethodDef Dialect_methods[] = {
+	{ NULL, NULL }
+};
+
+#define D_OFF(x) offsetof(DialectObj, x)
+
+static struct PyMemberDef Dialect_memberlist[] = {
+	{ "quotechar",          T_CHAR, D_OFF(quotechar) },
+	{ "delimiter",          T_CHAR, D_OFF(delimiter) },
+	{ "skipinitialspace",   T_INT, D_OFF(skipinitialspace) },
+	{ "doublequote",        T_INT, D_OFF(doublequote) },
+	{ "strict",             T_INT, D_OFF(strict) },
+	{ NULL }
+};
+
+static PyGetSetDef Dialect_getsetlist[] = {
+        { "escapechar", (getter)Dialect_get_escapechar, 
+                (setter)Dialect_set_escapechar },
+        { "lineterminator", (getter)Dialect_get_lineterminator, 
+                (setter)Dialect_set_lineterminator },
+        { "quoting", (getter)Dialect_get_quoting, 
+                (setter)Dialect_set_quoting },
+        {NULL},
+};
+
+static void
+Dialect_dealloc(DialectObj *self)
+{
+        Py_XDECREF(self->lineterminator);
+	/*PyMem_DEL(self);*/
+        self->ob_type->tp_free((PyObject *)self);
+}
+
+static int
+dialect_init(DialectObj * self, PyObject * args, PyObject * kwargs)
+{
+        PyObject *dialect = NULL, *name_obj, *value_obj;
+
+	self->quotechar = '"';
+	self->delimiter = ',';
+	self->escapechar = '\0';
+	self->skipinitialspace = 0;
+        Py_XDECREF(self->lineterminator);
+	self->lineterminator = PyString_FromString("\r\n");
+        if (self->lineterminator == NULL)
+                return -1;
+	self->quoting = QUOTE_MINIMAL;
+	self->doublequote = 1;
+	self->strict = 0;
+
+        if (!PyArg_ParseTuple(args, "|O", &dialect))
+                return -1;
+        Py_XINCREF(dialect);
+        if (kwargs != NULL) {
+                PyObject * key = PyString_FromString("dialect");
+                PyObject * d;
+
+                d = PyDict_GetItem(kwargs, key);
+                if (d) {
+                        Py_INCREF(d);
+                        Py_XDECREF(dialect);
+                        PyDict_DelItem(kwargs, key);
+                        dialect = d;
+                }
+                Py_DECREF(key);
+        }
+        if (dialect != NULL) {
+                int i;
+                PyObject * dir_list;
+
+                /* If dialect is a string, look it up in our registry */
+                if (PyString_Check(dialect) || PyUnicode_Check(dialect)) {
+                        PyObject * new_dia;
+                        new_dia = get_dialect_from_registry(dialect);
+                        Py_DECREF(dialect);
+                        if (new_dia == NULL)
+                                return -1;
+                        dialect = new_dia;
+                }
+                /* A class rather than an instance? Instanciate */
+                if (PyObject_TypeCheck(dialect, &PyClass_Type)) {
+                        PyObject * new_dia;
+                        new_dia = PyObject_CallFunction(dialect, "");
+                        Py_DECREF(dialect);
+                        if (new_dia == NULL)
+                                return -1;
+                        dialect = new_dia;
+                }
+                /* Make sure we finally have an instance */
+                if (!PyInstance_Check(dialect) ||
+                    (dir_list = PyObject_Dir(dialect)) == NULL) {
+                        PyErr_SetString(PyExc_TypeError,
+                                        "dialect must be an instance");
+                        Py_DECREF(dialect);
+                        return -1;
+                }
+                /* And extract the attributes */
+                for (i = 0; i < PyList_GET_SIZE(dir_list); ++i) {
+                        name_obj = PyList_GET_ITEM(dir_list, i);
+                        if (PyString_AsString(name_obj)[0] == '_')
+                                continue;
+                        value_obj = PyObject_GetAttr(dialect, name_obj);
+                        if (value_obj) {
+                                if (PyObject_SetAttr((PyObject *)self, 
+                                                     name_obj, value_obj)) {
+                                        Py_DECREF(dir_list);
+                                        return -1;
+                                }
+                                Py_DECREF(value_obj);
+                        }
+                }
+                Py_DECREF(dir_list);
+                Py_DECREF(dialect);
+        }
+        if (kwargs != NULL) {
+                int pos = 0;
+
+                while (PyDict_Next(kwargs, &pos, &name_obj, &value_obj)) {
+                        if (PyObject_SetAttr((PyObject *)self, 
+                                             name_obj, value_obj))
+                                return -1;
+                }
+        }
+        return 0;
+}
+
+static PyObject *
+dialect_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
+{
+        DialectObj *self;
+        self = (DialectObj *)type->tp_alloc(type, 0);
+        if (self != NULL) {
+                self->lineterminator = NULL;
+        }
+        return (PyObject *)self;
+}
+
+
+PyDoc_STRVAR(Dialect_Type_doc, 
+"CSV dialect\n"
+"\n"
+"The Dialect type records CSV parsing and generation options.\n");
+
+static PyTypeObject Dialect_Type = {
+	PyObject_HEAD_INIT(NULL)
+	0,                                      /* ob_size */
+	"_csv.Dialect",                         /* tp_name */
+	sizeof(DialectObj),                     /* tp_basicsize */
+	0,                                      /* tp_itemsize */
+	/*  methods  */
+	(destructor)Dialect_dealloc,            /* tp_dealloc */
+	(printfunc)0,                           /* tp_print */
+	(getattrfunc)0,                         /* tp_getattr */
+	(setattrfunc)0,                         /* tp_setattr */
+	(cmpfunc)0,                             /* tp_compare */
+	(reprfunc)0,                            /* tp_repr */
+	0,                                      /* tp_as_number */
+	0,                                      /* tp_as_sequence */
+	0,                                      /* tp_as_mapping */
+	(hashfunc)0,                            /* tp_hash */
+	(ternaryfunc)0,                         /* tp_call */
+	(reprfunc)0,                    	/* tp_str */
+	0,                                      /* tp_getattro */
+        0,                                      /* tp_setattro */
+        0,                                      /* tp_as_buffer */
+        Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
+	Dialect_Type_doc,                       /* tp_doc */
+        0,                                      /* tp_traverse */
+        0,                                      /* tp_clear */
+        0,                                      /* tp_richcompare */
+        0,                                      /* tp_weaklistoffset */
+        0,                                      /* tp_iter */
+        0,                                      /* tp_iternext */
+        Dialect_methods,                        /* tp_methods */
+        Dialect_memberlist,                     /* tp_members */
+        Dialect_getsetlist,                     /* tp_getset */
+	0,					/* tp_base */
+	0,					/* tp_dict */
+	0,					/* tp_descr_get */
+	0,					/* tp_descr_set */
+	0,					/* tp_dictoffset */
+	(initproc)dialect_init,			/* tp_init */
+	PyType_GenericAlloc,	                /* tp_alloc */
+	dialect_new,			        /* tp_new */
+	0,                           /* tp_free */
+};
+
+static void
+parse_save_field(ReaderObj *self)
+{
+	PyObject *field;
+
+	field = PyString_FromStringAndSize(self->field, self->field_len);
+	if (field != NULL) {
+		PyList_Append(self->fields, field);
+		Py_XDECREF(field);
+	}
+	self->field_len = 0;
+}
+
+static int
+parse_grow_buff(ReaderObj *self)
+{
+	if (self->field_size == 0) {
+		self->field_size = 4096;
+		self->field = PyMem_Malloc(self->field_size);
+	}
+	else {
+		self->field_size *= 2;
+		self->field = PyMem_Realloc(self->field, self->field_size);
+	}
+	if (self->field == NULL) {
+		PyErr_NoMemory();
+		return 0;
+	}
+	return 1;
+}
+
+static void
+parse_add_char(ReaderObj *self, char c)
+{
+	if (self->field_len == self->field_size && !parse_grow_buff(self))
+		return;
+	self->field[self->field_len++] = c;
+}
+
+static void
+parse_process_char(ReaderObj *self, char c)
+{
+        DialectObj *dialect = self->dialect;
+
+	switch (self->state) {
+	case START_RECORD:
+		/* start of record */
+		if (c == '\n')
+			/* empty line - return [] */
+			break;
+		/* normal character - handle as START_FIELD */
+		self->state = START_FIELD;
+		/* fallthru */
+	case START_FIELD:
+		/* expecting field */
+		if (c == '\n') {
+			/* save empty field - return [fields] */
+			parse_save_field(self);
+			self->state = START_RECORD;
+		}
+		else if (c == dialect->quotechar) {
+			/* start quoted field */
+			self->state = IN_QUOTED_FIELD;
+		}
+		else if (c == dialect->escapechar) {
+			/* possible escaped character */
+			self->state = ESCAPED_CHAR;
+		}
+		else if (c == ' ' && dialect->skipinitialspace)
+			/* ignore space at start of field */
+			;
+		else if (c == dialect->delimiter) {
+			/* save empty field */
+			parse_save_field(self);
+		}
+		else {
+			/* begin new unquoted field */
+			parse_add_char(self, c);
+			self->state = IN_FIELD;
+		}
+		break;
+
+	case ESCAPED_CHAR:
+		if (c != dialect->escapechar && 
+                    c != dialect->delimiter &&
+		    c != dialect->quotechar)
+			parse_add_char(self, dialect->escapechar);
+		parse_add_char(self, c);
+		self->state = IN_FIELD;
+		break;
+
+	case IN_FIELD:
+		/* in unquoted field */
+		if (c == '\n') {
+			/* end of line - return [fields] */
+			parse_save_field(self);
+			self->state = START_RECORD;
+		}
+		else if (c == dialect->escapechar) {
+			/* possible escaped character */
+			self->state = ESCAPED_CHAR;
+		}
+		else if (c == dialect->delimiter) {
+			/* save field - wait for new field */
+			parse_save_field(self);
+			self->state = START_FIELD;
+		}
+		else {
+			/* normal character - save in field */
+			parse_add_char(self, c);
+		}
+		break;
+
+	case IN_QUOTED_FIELD:
+		/* in quoted field */
+		if (c == '\n') {
+			/* end of line - save '\n' in field */
+			parse_add_char(self, '\n');
+		}
+		else if (c == dialect->escapechar) {
+			/* Possible escape character */
+			self->state = ESCAPE_IN_QUOTED_FIELD;
+		}
+		else if (c == dialect->quotechar) {
+			if (dialect->doublequote) {
+				/* doublequote; " represented by "" */
+				self->state = QUOTE_IN_QUOTED_FIELD;
+			}
+			else {
+				/* end of quote part of field */
+				self->state = IN_FIELD;
+			}
+		}
+		else {
+			/* normal character - save in field */
+			parse_add_char(self, c);
+		}
+		break;
+
+	case ESCAPE_IN_QUOTED_FIELD:
+		if (c != dialect->escapechar && 
+                    c != dialect->delimiter &&
+		    c != dialect->quotechar)
+			parse_add_char(self, dialect->escapechar);
+		parse_add_char(self, c);
+		self->state = IN_QUOTED_FIELD;
+		break;
+
+	case QUOTE_IN_QUOTED_FIELD:
+		/* doublequote - seen a quote in an quoted field */
+		if (dialect->quoting != QUOTE_NONE && 
+                    c == dialect->quotechar) {
+			/* save "" as " */
+			parse_add_char(self, c);
+			self->state = IN_QUOTED_FIELD;
+		}
+		else if (c == dialect->delimiter) {
+			/* save field - wait for new field */
+			parse_save_field(self);
+			self->state = START_FIELD;
+		}
+		else if (c == '\n') {
+			/* end of line - return [fields] */
+			parse_save_field(self);
+			self->state = START_RECORD;
+		}
+		else if (!dialect->strict) {
+			parse_add_char(self, c);
+			self->state = IN_FIELD;
+		}
+		else {
+			/* illegal */
+			self->had_parse_error = 1;
+			PyErr_Format(error_obj, "%c expected after %c", 
+					dialect->delimiter, 
+                                        dialect->quotechar);
+		}
+		break;
+
+	}
+}
+
+/*
+ * READER
+ */
+#define R_OFF(x) offsetof(ReaderObj, x)
+
+static struct PyMemberDef Reader_memberlist[] = {
+	{ "dialect", T_OBJECT, R_OFF(dialect), RO },
+	{ NULL }
+};
+
+static PyObject *
+Reader_getiter(ReaderObj *self)
+{
+	Py_INCREF(self);
+	return (PyObject *)self;
+}
+
+static PyObject *
+Reader_iternext(ReaderObj *self)
+{
+        PyObject *lineobj;
+        PyObject *fields;
+        char *line;
+
+        do {
+                lineobj = PyIter_Next(self->input_iter);
+                if (lineobj == NULL) {
+                        /* End of input OR exception */
+                        if (!PyErr_Occurred() && self->field_len != 0)
+                                return PyErr_Format(error_obj,
+                                                    "newline inside string");
+                        return NULL;
+                }
+
+                if (self->had_parse_error) {
+                        if (self->fields) {
+                                Py_XDECREF(self->fields);
+                        }
+                        self->fields = PyList_New(0);
+                        self->field_len = 0;
+                        self->state = START_RECORD;
+                        self->had_parse_error = 0;
+                }
+                line = PyString_AsString(lineobj);
+
+                if (line == NULL) {
+                        Py_DECREF(lineobj);
+                        return NULL;
+                }
+		if (strlen(line) < PyString_GET_SIZE(lineobj)) {
+			self->had_parse_error = 1;
+			Py_DECREF(lineobj);
+			return PyErr_Format(error_obj,
+					    "string with NUL bytes");
+		}
+
+                /* Process line of text - send '\n' to processing code to
+                represent end of line.  End of line which is not at end of
+                string is an error. */
+                while (*line) {
+                        char c;
+
+                        c = *line++;
+                        if (c == '\r') {
+                                c = *line++;
+                                if (c == '\0')
+                                        /* macintosh end of line */
+                                        break;
+                                if (c == '\n') {
+                                        c = *line++;
+                                        if (c == '\0')
+                                                /* DOS end of line */
+                                                break;
+                                }
+                                self->had_parse_error = 1;
+                                Py_DECREF(lineobj);
+                                return PyErr_Format(error_obj,
+                                                    "newline inside string");
+                        }
+                        if (c == '\n') {
+                                c = *line++;
+                                if (c == '\0')
+                                        /* unix end of line */
+                                        break;
+                                self->had_parse_error = 1;
+                                Py_DECREF(lineobj);
+                                return PyErr_Format(error_obj, 
+                                                    "newline inside string");
+                        }
+                        parse_process_char(self, c);
+                        if (PyErr_Occurred()) {
+                                Py_DECREF(lineobj);
+                                return NULL;
+                        }
+                }
+                parse_process_char(self, '\n');
+                Py_DECREF(lineobj);
+        } while (self->state != START_RECORD);
+
+        fields = self->fields;
+        self->fields = PyList_New(0);
+        return fields;
+}
+
+static void
+Reader_dealloc(ReaderObj *self)
+{
+        Py_XDECREF(self->dialect);
+        Py_XDECREF(self->input_iter);
+        Py_XDECREF(self->fields);
+	PyMem_DEL(self);
+}
+
+PyDoc_STRVAR(Reader_Type_doc,
+"CSV reader\n"
+"\n"
+"Reader objects are responsible for reading and parsing tabular data\n"
+"in CSV format.\n"
+);
+
+static struct PyMethodDef Reader_methods[] = {
+	{ NULL, NULL }
+};
+
+static PyTypeObject Reader_Type = {
+	PyObject_HEAD_INIT(NULL)
+	0,                                      /*ob_size*/
+	"_csv.reader",                          /*tp_name*/
+	sizeof(ReaderObj),                      /*tp_basicsize*/
+	0,                                      /*tp_itemsize*/
+	/* methods */
+	(destructor)Reader_dealloc,             /*tp_dealloc*/
+	(printfunc)0,                           /*tp_print*/
+	(getattrfunc)0,                         /*tp_getattr*/
+	(setattrfunc)0,                         /*tp_setattr*/
+	(cmpfunc)0,                             /*tp_compare*/
+	(reprfunc)0,                            /*tp_repr*/
+	0,                                      /*tp_as_number*/
+	0,                                      /*tp_as_sequence*/
+	0,                                      /*tp_as_mapping*/
+	(hashfunc)0,                            /*tp_hash*/
+	(ternaryfunc)0,                         /*tp_call*/
+	(reprfunc)0,                    	/*tp_str*/
+	0,                                      /*tp_getattro*/
+        0,                                      /*tp_setattro*/
+        0,                                      /*tp_as_buffer*/
+        Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/
+	Reader_Type_doc,                        /*tp_doc*/
+        0,                                      /*tp_traverse*/
+        0,                                      /*tp_clear*/
+        0,                                      /*tp_richcompare*/
+        0,                                      /*tp_weaklistoffset*/
+        (getiterfunc)Reader_getiter,            /*tp_iter*/
+        (getiterfunc)Reader_iternext,           /*tp_iternext*/
+        Reader_methods,                         /*tp_methods*/
+        Reader_memberlist,                      /*tp_members*/
+        0,                                      /*tp_getset*/
+
+};
+
+static PyObject *
+csv_reader(PyObject *module, PyObject *args, PyObject *keyword_args)
+{
+        PyObject * iterator, * dialect = NULL, *ctor_args;
+        ReaderObj * self = PyObject_NEW(ReaderObj, &Reader_Type);
+
+        if (!self)
+                return NULL;
+
+        self->dialect = NULL;
+        self->input_iter = self->fields = NULL;
+
+        self->fields = NULL;
+        self->input_iter = NULL;
+	self->had_parse_error = 0;
+	self->field = NULL;
+	self->field_size = 0;
+	self->field_len = 0;
+	self->state = START_RECORD;
+
+        if (!PyArg_ParseTuple(args, "O|O", &iterator, &dialect)) {
+                Py_DECREF(self);
+                return NULL;
+        }
+        self->input_iter = PyObject_GetIter(iterator);
+        if (self->input_iter == NULL) {
+                PyErr_SetString(PyExc_TypeError, 
+                                "argument 1 must be an iterator");
+                Py_DECREF(self);
+                return NULL;
+        }
+        ctor_args = Py_BuildValue(dialect ? "(O)" : "()", dialect);
+        if (ctor_args == NULL) {
+                Py_DECREF(self);
+                return NULL;
+        }
+        self->dialect = (DialectObj *)PyObject_Call((PyObject *)&Dialect_Type,
+                                                    ctor_args, keyword_args);
+        Py_DECREF(ctor_args);
+        if (self->dialect == NULL) {
+                Py_DECREF(self);
+                return NULL;
+        }
+	self->fields = PyList_New(0);
+	if (self->fields == NULL) {
+		Py_DECREF(self);
+		return NULL;
+	}
+
+        return (PyObject *)self;
+}
+
+/*
+ * WRITER
+ */
+/* ---------------------------------------------------------------- */
+static void
+join_reset(WriterObj *self)
+{
+	self->rec_len = 0;
+	self->num_fields = 0;
+}
+
+#define MEM_INCR 32768
+
+/* Calculate new record length or append field to record.  Return new
+ * record length.
+ */
+static int
+join_append_data(WriterObj *self, char *field, int quote_empty,
+		 int *quoted, int copy_phase)
+{
+        DialectObj *dialect = self->dialect;
+	int i, rec_len;
+
+	rec_len = self->rec_len;
+
+	/* If this is not the first field we need a field separator.
+	 */
+	if (self->num_fields > 0) {
+		if (copy_phase)
+			self->rec[rec_len] = dialect->delimiter;
+		rec_len++;
+	}
+	/* Handle preceding quote.
+	 */
+	switch (dialect->quoting) {
+	case QUOTE_ALL:
+		*quoted = 1;
+		if (copy_phase)
+			self->rec[rec_len] = dialect->quotechar;
+		rec_len++;
+		break;
+	case QUOTE_MINIMAL:
+	case QUOTE_NONNUMERIC:
+		/* We only know about quoted in the copy phase.
+		 */
+		if (copy_phase && *quoted) {
+			self->rec[rec_len] = dialect->quotechar;
+			rec_len++;
+		}
+		break;
+	case QUOTE_NONE:
+		break;
+	}
+	/* Copy/count field data.
+	 */
+	for (i = 0;; i++) {
+		char c = field[i];
+
+		if (c == '\0')
+			break;
+		/* If in doublequote mode we escape quote chars with a
+		 * quote.
+		 */
+		if (dialect->quoting != QUOTE_NONE && 
+                    c == dialect->quotechar && dialect->doublequote) {
+			if (copy_phase)
+				self->rec[rec_len] = dialect->quotechar;
+			*quoted = 1;
+			rec_len++;
+		}
+
+		/* Some special characters need to be escaped.  If we have a
+		 * quote character switch to quoted field instead of escaping
+		 * individual characters.
+		 */
+		if (!*quoted
+		    && (c == dialect->delimiter || 
+                        c == dialect->escapechar || 
+                        c == '\n' || c == '\r')) {
+			if (dialect->quoting != QUOTE_NONE)
+				*quoted = 1;
+			else if (dialect->escapechar) {
+				if (copy_phase)
+					self->rec[rec_len] = dialect->escapechar;
+				rec_len++;
+			}
+			else {
+				PyErr_Format(error_obj, 
+                                             "delimiter must be quoted or escaped");
+				return -1;
+			}
+		}
+		/* Copy field character into record buffer.
+		 */
+		if (copy_phase)
+			self->rec[rec_len] = c;
+		rec_len++;
+	}
+
+	/* If field is empty check if it needs to be quoted.
+	 */
+	if (i == 0 && quote_empty) {
+		if (dialect->quoting == QUOTE_NONE) {
+			PyErr_Format(error_obj,
+                                     "single empty field record must be quoted");
+			return -1;
+		} else
+			*quoted = 1;
+	}
+
+	/* Handle final quote character on field.
+	 */
+	if (*quoted) {
+		if (copy_phase)
+			self->rec[rec_len] = dialect->quotechar;
+		else
+			/* Didn't know about leading quote until we found it
+			 * necessary in field data - compensate for it now.
+			 */
+			rec_len++;
+		rec_len++;
+	}
+
+	return rec_len;
+}
+
+static int
+join_check_rec_size(WriterObj *self, int rec_len)
+{
+	if (rec_len > self->rec_size) {
+		if (self->rec_size == 0) {
+			self->rec_size = (rec_len / MEM_INCR + 1) * MEM_INCR;
+			self->rec = PyMem_Malloc(self->rec_size);
+		}
+		else {
+			char *old_rec = self->rec;
+
+			self->rec_size = (rec_len / MEM_INCR + 1) * MEM_INCR;
+			self->rec = PyMem_Realloc(self->rec, self->rec_size);
+			if (self->rec == NULL)
+				PyMem_Free(old_rec);
+		}
+		if (self->rec == NULL) {
+			PyErr_NoMemory();
+			return 0;
+		}
+	}
+	return 1;
+}
+
+static int
+join_append(WriterObj *self, char *field, int *quoted, int quote_empty)
+{
+	int rec_len;
+
+	rec_len = join_append_data(self, field, quote_empty, quoted, 0);
+	if (rec_len < 0)
+		return 0;
+
+	/* grow record buffer if necessary */
+	if (!join_check_rec_size(self, rec_len))
+		return 0;
+
+	self->rec_len = join_append_data(self, field, quote_empty, quoted, 1);
+	self->num_fields++;
+
+	return 1;
+}
+
+static int
+join_append_lineterminator(WriterObj *self)
+{
+	int terminator_len;
+
+	terminator_len = PyString_Size(self->dialect->lineterminator);
+
+	/* grow record buffer if necessary */
+	if (!join_check_rec_size(self, self->rec_len + terminator_len))
+		return 0;
+
+	memmove(self->rec + self->rec_len,
+		PyString_AsString(self->dialect->lineterminator), 
+                terminator_len);
+	self->rec_len += terminator_len;
+
+	return 1;
+}
+
+PyDoc_STRVAR(csv_writerow_doc,
+"join(sequence) -> string\n"
+"\n"
+"Construct a CSV record from a sequence of fields.  Non-string\n"
+"elements will be converted to string.");
+
+static PyObject *
+csv_writerow(WriterObj *self, PyObject *seq)
+{
+        DialectObj *dialect = self->dialect;
+	int len, i;
+
+	if (!PySequence_Check(seq))
+		return PyErr_Format(error_obj, "sequence expected");
+
+	len = PySequence_Length(seq);
+	if (len < 0)
+		return NULL;
+
+	/* Join all fields in internal buffer.
+	 */
+	join_reset(self);
+	for (i = 0; i < len; i++) {
+		PyObject *field;
+		int append_ok;
+		int quoted;
+
+		field = PySequence_GetItem(seq, i);
+		if (field == NULL)
+			return NULL;
+
+		quoted = 0;
+		if (dialect->quoting == QUOTE_NONNUMERIC) {
+			PyObject *num;
+
+			num = PyNumber_Float(field);
+			if (num == NULL) {
+				quoted = 1;
+				PyErr_Clear();
+			}
+			else {
+				Py_DECREF(num);
+			}
+		}
+
+		if (PyString_Check(field)) {
+			append_ok = join_append(self, PyString_AsString(field),
+                                                &quoted, len == 1);
+			Py_DECREF(field);
+		}
+		else if (field == Py_None) {
+			append_ok = join_append(self, "", &quoted, len == 1);
+			Py_DECREF(field);
+		}
+		else {
+			PyObject *str;
+
+			str = PyObject_Str(field);
+			Py_DECREF(field);
+			if (str == NULL)
+				return NULL;
+
+			append_ok = join_append(self, PyString_AsString(str), 
+                                                &quoted, len == 1);
+			Py_DECREF(str);
+		}
+		if (!append_ok)
+			return NULL;
+	}
+
+	/* Add line terminator.
+	 */
+	if (!join_append_lineterminator(self))
+		return 0;
+
+	return PyObject_CallFunction(self->writeline, 
+                                     "(s#)", self->rec, self->rec_len);
+}
+
+static PyObject *
+csv_writerows(WriterObj *self, PyObject *seqseq)
+{
+        PyObject *row_iter, *row_obj, *result;
+
+        row_iter = PyObject_GetIter(seqseq);
+        if (row_iter == NULL) {
+                PyErr_SetString(PyExc_TypeError,
+                                "writerows() argument must be iteratable");
+                return NULL;
+        }
+        while ((row_obj = PyIter_Next(row_iter))) {
+                result = csv_writerow(self, row_obj);
+                Py_DECREF(row_obj);
+                if (!result) {
+                        Py_DECREF(row_iter);
+                        return NULL;
+                }
+                else
+                     Py_DECREF(result);   
+        }
+        Py_DECREF(row_iter);
+        if (PyErr_Occurred())
+                return NULL;
+        Py_INCREF(Py_None);
+        return Py_None;
+}
+
+static struct PyMethodDef Writer_methods[] = {
+        { "writerow", (PyCFunction)csv_writerow, METH_O, csv_writerow_doc},
+        { "writerows", (PyCFunction)csv_writerows, METH_O},
+	{ NULL, NULL }
+};
+
+#define W_OFF(x) offsetof(WriterObj, x)
+
+static struct PyMemberDef Writer_memberlist[] = {
+	{ "dialect", T_OBJECT, W_OFF(dialect), RO },
+	{ NULL }
+};
+
+static void
+Writer_dealloc(WriterObj *self)
+{
+        Py_XDECREF(self->dialect);
+        Py_XDECREF(self->writeline);
+	PyMem_DEL(self);
+}
+
+PyDoc_STRVAR(Writer_Type_doc, 
+"CSV writer\n"
+"\n"
+"Writer objects are responsible for generating tabular data\n"
+"in CSV format from sequence input.\n"
+);
+
+static PyTypeObject Writer_Type = {
+	PyObject_HEAD_INIT(NULL)
+	0,                                      /*ob_size*/
+	"_csv.writer",                          /*tp_name*/
+	sizeof(WriterObj),                      /*tp_basicsize*/
+	0,                                      /*tp_itemsize*/
+	/* methods */
+	(destructor)Writer_dealloc,             /*tp_dealloc*/
+	(printfunc)0,                           /*tp_print*/
+	(getattrfunc)0,                         /*tp_getattr*/
+	(setattrfunc)0,                         /*tp_setattr*/
+	(cmpfunc)0,                             /*tp_compare*/
+	(reprfunc)0,                            /*tp_repr*/
+	0,                                      /*tp_as_number*/
+	0,                                      /*tp_as_sequence*/
+	0,                                      /*tp_as_mapping*/
+	(hashfunc)0,                            /*tp_hash*/
+	(ternaryfunc)0,                         /*tp_call*/
+	(reprfunc)0,                            /*tp_str*/
+	0,                                      /*tp_getattro*/
+        0,                                      /*tp_setattro*/
+        0,                                      /*tp_as_buffer*/
+        Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/
+	Writer_Type_doc,
+        0,                                      /*tp_traverse*/
+        0,                                      /*tp_clear*/
+        0,                                      /*tp_richcompare*/
+        0,                                      /*tp_weaklistoffset*/
+        (getiterfunc)0,                         /*tp_iter*/
+        (getiterfunc)0,                         /*tp_iternext*/
+        Writer_methods,                         /*tp_methods*/
+        Writer_memberlist,                      /*tp_members*/
+        0,                                      /*tp_getset*/
+};
+
+static PyObject *
+csv_writer(PyObject *module, PyObject *args, PyObject *keyword_args)
+{
+        PyObject * output_file, * dialect = NULL, *ctor_args;
+        WriterObj * self = PyObject_NEW(WriterObj, &Writer_Type);
+
+        if (!self)
+                return NULL;
+
+        self->dialect = NULL;
+        self->writeline = NULL;
+
+	self->rec = NULL;
+	self->rec_size = 0;
+	self->rec_len = 0;
+	self->num_fields = 0;
+
+        if (!PyArg_ParseTuple(args, "O|O", &output_file, &dialect)) {
+                Py_DECREF(self);
+                return NULL;
+        }
+        self->writeline = PyObject_GetAttrString(output_file, "write");
+        if (self->writeline == NULL || !PyCallable_Check(self->writeline)) {
+                PyErr_SetString(PyExc_TypeError,
+                                "argument 1 must be an instance with a write method");
+                Py_DECREF(self);
+                return NULL;
+        }
+        ctor_args = Py_BuildValue(dialect ? "(O)" : "()", dialect);
+        if (ctor_args == NULL) {
+                Py_DECREF(self);
+                return NULL;
+        }
+        self->dialect = (DialectObj *)PyObject_Call((PyObject *)&Dialect_Type,
+                                                    ctor_args, keyword_args);
+        Py_DECREF(ctor_args);
+        if (self->dialect == NULL) {
+                Py_DECREF(self);
+                return NULL;
+        }
+        return (PyObject *)self;
+}
+
+/*
+ * DIALECT REGISTRY
+ */
+static PyObject *
+csv_list_dialects(PyObject *module, PyObject *args)
+{
+        return PyDict_Keys(dialects);
+}
+
+static PyObject *
+csv_register_dialect(PyObject *module, PyObject *args)
+{
+        PyObject *name_obj, *dialect_obj;
+
+        if (!PyArg_ParseTuple(args, "OO", &name_obj, &dialect_obj))
+                return NULL;
+        if (!PyString_Check(name_obj) && !PyUnicode_Check(name_obj)) {
+                PyErr_SetString(PyExc_TypeError, 
+                                "dialect name must be a string or unicode");
+                return NULL;
+        }
+        Py_INCREF(dialect_obj);
+        /* A class rather than an instance? Instanciate */
+        if (PyObject_TypeCheck(dialect_obj, &PyClass_Type)) {
+                PyObject * new_dia;
+                new_dia = PyObject_CallFunction(dialect_obj, "");
+                Py_DECREF(dialect_obj);
+                if (new_dia == NULL)
+                        return NULL;
+                dialect_obj = new_dia;
+        }
+        /* Make sure we finally have an instance */
+        if (!PyInstance_Check(dialect_obj)) {
+                PyErr_SetString(PyExc_TypeError, "dialect must be an instance");
+                Py_DECREF(dialect_obj);
+                return NULL;
+        }
+        if (PyObject_SetAttrString(dialect_obj, "_name", name_obj) < 0) {
+                Py_DECREF(dialect_obj);
+                return NULL;
+        }
+        if (PyDict_SetItem(dialects, name_obj, dialect_obj) < 0) {
+                Py_DECREF(dialect_obj);
+                return NULL;
+        }
+        Py_DECREF(dialect_obj);
+        Py_INCREF(Py_None);
+        return Py_None;
+}
+
+static PyObject *
+csv_unregister_dialect(PyObject *module, PyObject *args)
+{
+        PyObject *name_obj;
+
+        if (!PyArg_ParseTuple(args, "O", &name_obj))
+                return NULL;
+        if (PyDict_DelItem(dialects, name_obj) < 0)
+                return PyErr_Format(error_obj, "unknown dialect");
+        Py_INCREF(Py_None);
+        return Py_None;
+}
+
+static PyObject *
+csv_get_dialect(PyObject *module, PyObject *args)
+{
+        PyObject *name_obj;
+
+        if (!PyArg_ParseTuple(args, "O", &name_obj))
+                return NULL;
+        return get_dialect_from_registry(name_obj);
+}
+
+/*
+ * MODULE
+ */
+
+PyDoc_STRVAR(csv_module_doc,
+"CSV parsing and writing.\n"
+"\n"
+"This module provides classes that assist in the reading and writing\n"
+"of Comma Separated Value (CSV) files, and implements the interface\n"
+"described by PEP 305.  Although many CSV files are simple to parse,\n"
+"the format is not formally defined by a stable specification and\n"
+"is subtle enough that parsing lines of a CSV file with something\n"
+"like line.split(\",\") is bound to fail.  The module supports three\n"
+"basic APIs: reading, writing, and registration of dialects.\n"
+"\n"
+"\n"
+"DIALECT REGISTRATION:\n"
+"\n"
+"Readers and writers support a dialect argument, which is a convenient\n"
+"handle on a group of settings.  When the dialect argument is a string,\n"
+"it identifies one of the dialects previously registered with the module.\n"
+"If it is a class or instance, the attributes of the argument are used as\n"
+"the settings for the reader or writer:\n"
+"\n"
+"    class excel:\n"
+"        delimiter = ','\n"
+"        quotechar = '\"'\n"
+"        escapechar = None\n"
+"        doublequote = True\n"
+"        skipinitialspace = False\n"
+"        lineterminator = '\r\n'\n"
+"        quoting = QUOTE_MINIMAL\n"
+"\n"
+"SETTINGS:\n"
+"\n"
+"    * quotechar - specifies a one-character string to use as the \n"
+"        quoting character.  It defaults to '\"'.\n"
+"    * delimiter - specifies a one-character string to use as the \n"
+"        field separator.  It defaults to ','.\n"
+"    * skipinitialspace - specifies how to interpret whitespace which\n"
+"        immediately follows a delimiter.  It defaults to False, which\n"
+"        means that whitespace immediately following a delimiter is part\n"
+"        of the following field.\n"
+"    * lineterminator -  specifies the character sequence which should \n"
+"        terminate rows.\n"
+"    * quoting - controls when quotes should be generated by the writer.\n"
+"        It can take on any of the following module constants:\n"
+"\n"
+"        csv.QUOTE_MINIMAL means only when required, for example, when a\n"
+"            field contains either the quotechar or the delimiter\n"
+"        csv.QUOTE_ALL means that quotes are always placed around fields.\n"
+"        csv.QUOTE_NONNUMERIC means that quotes are always placed around\n"
+"            fields which contain characters other than [+-0-9.].\n"
+"        csv.QUOTE_NONE means that quotes are never placed around fields.\n"
+"    * escapechar - specifies a one-character string used to escape \n"
+"        the delimiter when quoting is set to QUOTE_NONE.\n"
+"    * doublequote - controls the handling of quotes inside fields.  When\n"
+"        True, two consecutive quotes are interpreted as one during read,\n"
+"        and when writing, each quote character embedded in the data is\n"
+"        written as two quotes\n");
+
+PyDoc_STRVAR(csv_reader_doc,
+"    csv_reader = reader(iterable [, dialect='excel']\n"
+"                        [optional keyword args])\n"
+"    for row in csv_reader:\n"
+"        process(row)\n"
+"\n"
+"The \"iterable\" argument can be any object that returns a line\n"
+"of input for each iteration, such as a file object or a list.  The\n"
+"optional \"dialect\" parameter is discussed below.  The function\n"
+"also accepts optional keyword arguments which override settings\n"
+"provided by the dialect.\n"
+"\n"
+"The returned object is an iterator.  Each iteration returns a row\n"
+	     "of the CSV file (which can span multiple input lines):\n");
+
+PyDoc_STRVAR(csv_writer_doc,
+"    csv_writer = csv.writer(fileobj [, dialect='excel']\n"
+"                            [optional keyword args])\n"
+"    for row in csv_writer:\n"
+"        csv_writer.writerow(row)\n"
+"\n"
+"    [or]\n"
+"\n"
+"    csv_writer = csv.writer(fileobj [, dialect='excel']\n"
+"                            [optional keyword args])\n"
+"    csv_writer.writerows(rows)\n"
+"\n"
+"The \"fileobj\" argument can be any object that supports the file API.\n");
+
+PyDoc_STRVAR(csv_list_dialects_doc,
+"Return a list of all know dialect names.\n"
+"    names = csv.list_dialects()");
+
+PyDoc_STRVAR(csv_get_dialect_doc,
+"Return the dialect instance associated with name.\n"
+"    dialect = csv.get_dialect(name)");
+
+PyDoc_STRVAR(csv_register_dialect_doc,
+"Create a mapping from a string name to a dialect class.\n"
+"    dialect = csv.register_dialect(name, dialect)");
+
+PyDoc_STRVAR(csv_unregister_dialect_doc,
+"Delete the name/dialect mapping associated with a string name.\n"
+"    csv.unregister_dialect(name)");
+
+static struct PyMethodDef csv_methods[] = {
+        { "reader", (PyCFunction)csv_reader, 
+            METH_VARARGS | METH_KEYWORDS, csv_reader_doc},
+        { "writer", (PyCFunction)csv_writer, 
+            METH_VARARGS | METH_KEYWORDS, csv_writer_doc},
+        { "list_dialects", (PyCFunction)csv_list_dialects, 
+            METH_NOARGS, csv_list_dialects_doc},
+        { "register_dialect", (PyCFunction)csv_register_dialect, 
+            METH_VARARGS, csv_register_dialect_doc},
+        { "unregister_dialect", (PyCFunction)csv_unregister_dialect, 
+            METH_VARARGS, csv_unregister_dialect_doc},
+        { "get_dialect", (PyCFunction)csv_get_dialect, 
+            METH_VARARGS, csv_get_dialect_doc},
+        { NULL, NULL }
+};
+
+PyMODINIT_FUNC
+init_csv(void)
+{
+	PyObject *module;
+	PyObject *rev;
+	PyObject *v;
+	int res;
+	StyleDesc *style;
+
+	if (PyType_Ready(&Dialect_Type) < 0)
+		return;
+
+	if (PyType_Ready(&Reader_Type) < 0)
+		return;
+
+	if (PyType_Ready(&Writer_Type) < 0)
+		return;
+
+	/* Create the module and add the functions */
+	module = Py_InitModule3("_csv", csv_methods, csv_module_doc);
+	if (module == NULL)
+		return;
+
+	/* Add version to the module. */
+	rev = PyString_FromString("1.0");
+	if (rev == NULL)
+		return;
+        if (PyModule_AddObject(module, "__version__", rev) < 0)
+		return;
+
+        /* Add _dialects dictionary */
+        dialects = PyDict_New();
+        if (dialects == NULL)
+                return;
+        if (PyModule_AddObject(module, "_dialects", dialects))
+                return;
+
+	/* Add quote styles into dictionary */
+	for (style = quote_styles; style->name; style++) {
+		v = PyInt_FromLong(style->style);
+		if (v == NULL)
+			return;
+		res = PyModule_AddObject(module, style->name, v);
+		if (res < 0)
+			return;
+	}
+
+        /* Add the Dialect type */
+        if (PyModule_AddObject(module, "Dialect", (PyObject *)&Dialect_Type))
+                return;
+
+	/* Add the CSV exception object to the module. */
+	error_obj = PyErr_NewException("_csv.Error", NULL, NULL);
+	if (error_obj == NULL)
+		return;
+	PyModule_AddObject(module, "Error", error_obj);
+}