def test_table_column_name_freed(self):
c_string = ctypes.create_string_buffer(b'Foo!')
with mock.patch.object(_lib, 'TableColumnName', return_value=c_string):
table = _lib.TableNew()
binding = Binding(table)
self.assertEqual(binding.table_column_name(0), 'Foo!')
_lib.StringFree.assert_called_once_with(c_string)
def __init__(self, schema):
schema = self.validate_schema(schema)
self._table_ptr = Binding.table_new()
self.binding = Binding(self._table_ptr)
self._init_columns(schema)
self._len_changed = True
class Table:
VALID_COLUMN_NAME = re.compile(r'^[A-Za-z\d]+$')
VALID_COLUMN_TYPES = {'string': str, 'int': int}
def __init__(self, schema):
schema = self.validate_schema(schema)
self._table_ptr = Binding.table_new()
self.binding = Binding(self._table_ptr)
self._init_columns(schema)
self._len_changed = True
@classmethod
def validate_schema(cls, schema):
for column in schema:
if len(column) != 2:
raise TypeError('Expected schema format is [(name, type), (name, type) ...]')
if not cls.VALID_COLUMN_NAME.match(column[0]):
raise ValueError('Invalid column name %s: it must only contain letters and numbers.' % column[0])
if column[1] not in cls.VALID_COLUMN_TYPES:
raise TypeError('Invalid column type: %s: it must be one of %s' % (column[1], cls.VALID_COLUMN_TYPES))
return schema
def _init_columns(self, schema):
self.binding.init_columns(schema)
@property
def width(self):
return self.binding.table_width()
@property
def column_names(self):
"""An list of column names in the schema."""
return [self.binding.table_column_name(i) for i in range(self.width)]
@property
def column_types(self):
"""An list of column types in the schema."""
return [self.binding.table_column_type(i) for i in range(self.width)]
@property
def schema(self):
"""Return the schema of the table."""
return list(zip(self.column_names, self.column_types))
def append(self, row):
for (name, typ), element in zip(self.schema, row):
if not isinstance(element, self.VALID_COLUMN_TYPES[typ]):
raise TypeError('Column %s expects %s, got %s.' % (
name,
self.VALID_COLUMN_TYPES[typ],
type(element)
))
self.binding.table_append(row)
self._len_changed = True
def extend(self, rows):
for row in rows:
self.append(row)
def __len__(self):
if self._len_changed:
self._len = self.binding.table_len()
self._len_changed = False
return self._len
def __getitem__(self, row_index):
if row_index < 0:
row_index = abs(row_index + len(self))
if row_index > len(self) - 1:
raise IndexError('Table index out of range')
return self.binding.table_row(row_index)
def __del__(self):
"""Free the underlying table.
In case Table instatiation failing, then there is nothing to free.
"""
try:
self.binding.table_free()
except AttributeError:
pass
def test_py_str(self):
c_string = ctypes.create_string_buffer(b'Foo!')
self.assertEqual(Binding.py_str(c_string), 'Foo!')