traverseda
/
cpython
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Issue #23171: csv.Writer.writerow() now supports arbitrary iterables.

This commit is contained in:
Serhiy Storchaka 2015-03-30 09:09:54 +03:00
parent a695f83f0d
commit 7901b48a1f
5 changed files with 54 additions and 46 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
Doc/library/csv.rst
View File

@ -419,7 +419,7 @@ Writer Objects
:class:`Writer` objects (:class:`DictWriter` instances and objects returned by
the :func:`writer` function) have the following public methods. A *row* must be
a sequence of strings or numbers for :class:`Writer` objects and a dictionary
an iterable of strings or numbers for :class:`Writer` objects and a dictionary
mapping fieldnames to strings or numbers (by passing them through :func:`str`
first) for :class:`DictWriter` objects. Note that complex numbers are written
out surrounded by parens. This may cause some problems for other programs which
@ -431,6 +431,8 @@ read CSV files (assuming they support complex numbers at all).
Write the *row* parameter to the writer's file object, formatted according to
the current dialect.
.. versionchanged:: 3.5
Added support of arbitrary iterables.
.. method:: csvwriter.writerows(rows)

7
Lib/csv.py
View File

@ -147,16 +147,13 @@ class DictWriter:
if wrong_fields:
raise ValueError("dict contains fields not in fieldnames: "
+ ", ".join([repr(x) for x in wrong_fields]))
return [rowdict.get(key, self.restval) for key in self.fieldnames]
return (rowdict.get(key, self.restval) for key in self.fieldnames)
def writerow(self, rowdict):
return self.writer.writerow(self._dict_to_list(rowdict))
def writerows(self, rowdicts):
rows = []
for rowdict in rowdicts:
rows.append(self._dict_to_list(rowdict))
return self.writer.writerows(rows)
return self.writer.writerows(map(self._dict_to_list, rowdicts))
# Guard Sniffer's type checking against builds that exclude complex()
try:

8
Lib/test/test_csv.py
View File

@ -186,6 +186,14 @@ class Test_Csv(unittest.TestCase):
self._write_test(['a',1,'p,q'], 'a,1,p\\,q',
escapechar='\\', quoting = csv.QUOTE_NONE)
def test_write_iterable(self):
self._write_test(iter(['a', 1, 'p,q']), 'a,1,"p,q"')
self._write_test(iter(['a', 1, None]), 'a,1,')
self._write_test(iter([]), '')
self._write_test(iter([None]), '""')
self._write_error_test(csv.Error, iter([None]), quoting=csv.QUOTE_NONE)
self._write_test(iter([None, None]), ',')
def test_writerows(self):
class BrokenFile:
def write(self, buf):

2
Misc/NEWS
View File

@ -56,6 +56,8 @@ Core and Builtins
Library
-------
- Issue #23171: csv.Writer.writerow() now supports arbitrary iterables.
- Issue #23745: The new email header parser now handles duplicate MIME
parameter names without error, similar to how get_param behaves.

79
Modules/_csv.c
View File

@ -1009,7 +1009,7 @@ join_reset(WriterObj *self)
*/
static Py_ssize_t
join_append_data(WriterObj *self, unsigned int field_kind, void *field_data,
Py_ssize_t field_len, int quote_empty, int *quoted,
Py_ssize_t field_len, int *quoted,
int copy_phase)
{
DialectObj *dialect = self->dialect;
@ -1071,18 +1071,6 @@ join_append_data(WriterObj *self, unsigned int field_kind, void *field_data,
ADDCH(c);
}
/* If field is empty check if it needs to be quoted.
*/
if (i == 0 && quote_empty) {
if (dialect->quoting == QUOTE_NONE) {
PyErr_Format(_csvstate_global->error_obj,
"single empty field record must be quoted");
return -1;
}
else
*quoted = 1;
}
if (*quoted) {
if (copy_phase)
ADDCH(dialect->quotechar);
@ -1126,7 +1114,7 @@ join_check_rec_size(WriterObj *self, Py_ssize_t rec_len)
}
static int
join_append(WriterObj *self, PyObject *field, int *quoted, int quote_empty)
join_append(WriterObj *self, PyObject *field, int quoted)
{
unsigned int field_kind = -1;
void *field_data = NULL;
@ -1141,7 +1129,7 @@ join_append(WriterObj *self, PyObject *field, int *quoted, int quote_empty)
field_len = PyUnicode_GET_LENGTH(field);
}
rec_len = join_append_data(self, field_kind, field_data, field_len,
quote_empty, quoted, 0);
&quoted, 0);
if (rec_len < 0)
return 0;
@ -1150,7 +1138,7 @@ join_append(WriterObj *self, PyObject *field, int *quoted, int quote_empty)
return 0;
self->rec_len = join_append_data(self, field_kind, field_data, field_len,
quote_empty, quoted, 1);
&quoted, 1);
self->num_fields++;
return 1;
@ -1181,37 +1169,30 @@ join_append_lineterminator(WriterObj *self)
}
PyDoc_STRVAR(csv_writerow_doc,
"writerow(sequence)\n"
"writerow(iterable)\n"
"\n"
"Construct and write a CSV record from a sequence of fields. Non-string\n"
"Construct and write a CSV record from an iterable of fields. Non-string\n"
"elements will be converted to string.");
static PyObject *
csv_writerow(WriterObj *self, PyObject *seq)
{
DialectObj *dialect = self->dialect;
Py_ssize_t len, i;
PyObject *line, *result;
PyObject *iter, *field, *line, *result;
if (!PySequence_Check(seq))
return PyErr_Format(_csvstate_global->error_obj, "sequence expected");
len = PySequence_Length(seq);
if (len < 0)
return NULL;
iter = PyObject_GetIter(seq);
if (iter == NULL)
return PyErr_Format(_csvstate_global->error_obj,
"iterable expected, not %.200s",
seq->ob_type->tp_name);
/* Join all fields in internal buffer.
*/
join_reset(self);
for (i = 0; i < len; i++) {
PyObject *field;
while ((field = PyIter_Next(iter))) {
int append_ok;
int quoted;
field = PySequence_GetItem(seq, i);
if (field == NULL)
return NULL;
switch (dialect->quoting) {
case QUOTE_NONNUMERIC:
quoted = !PyNumber_Check(field);
@ -1225,11 +1206,11 @@ csv_writerow(WriterObj *self, PyObject *seq)
}
if (PyUnicode_Check(field)) {
append_ok = join_append(self, field, &quoted, len == 1);
append_ok = join_append(self, field, quoted);
Py_DECREF(field);
}
else if (field == Py_None) {
append_ok = join_append(self, NULL, &quoted, len == 1);
append_ok = join_append(self, NULL, quoted);
Py_DECREF(field);
}
else {
@ -1237,19 +1218,37 @@ csv_writerow(WriterObj *self, PyObject *seq)
str = PyObject_Str(field);
Py_DECREF(field);
if (str == NULL)
if (str == NULL) {
Py_DECREF(iter);
return NULL;
append_ok = join_append(self, str, &quoted, len == 1);
}
append_ok = join_append(self, str, quoted);
Py_DECREF(str);
}
if (!append_ok)
if (!append_ok) {
Py_DECREF(iter);
return NULL;
}
}
Py_DECREF(iter);
if (PyErr_Occurred())
return NULL;
if (self->num_fields > 0 && self->rec_size == 0) {
if (dialect->quoting == QUOTE_NONE) {
PyErr_Format(_csvstate_global->error_obj,
"single empty field record must be quoted");
return NULL;
}
self->num_fields--;
if (!join_append(self, NULL, 1))
return NULL;
}
/* Add line terminator.
*/
if (!join_append_lineterminator(self))
return 0;
return NULL;
line = PyUnicode_FromKindAndData(PyUnicode_4BYTE_KIND,
(void *) self->rec, self->rec_len);
@ -1261,9 +1260,9 @@ csv_writerow(WriterObj *self, PyObject *seq)
}
PyDoc_STRVAR(csv_writerows_doc,
"writerows(sequence of sequences)\n"
"writerows(iterable of iterables)\n"
"\n"
"Construct and write a series of sequences to a csv file. Non-string\n"
"Construct and write a series of iterables to a csv file. Non-string\n"
"elements will be converted to string.");
static PyObject *