Merge branch 'stacking' into feature/stacking

tablib/core.py

@@ -547,6 +547,59 @@ class Dataset(object):
 			_dset.append(row=row_data)
 
 		return _dset
+	
+	def row_stack(self, other):
+
+		"""Stack two :class:`Dataset` instances together by
+		joining them at the row level, and return a new
+		combined ``Dataset`` instance."""
+
+		if not isinstance(other, Dataset):
+			return
+
+		if self.width != other.width:
+			raise InvalidDimensions
+
+		# Copy the source data
+		_dset = copy(self)
+		
+		rows_to_stack = [row for row in _dset._data]
+		other_rows = [row for row in other._data]
+
+		rows_to_stack.extend(other_rows)
+		_dset._data = rows_to_stack
+	
+		return _dset
+
+	def column_stack(self, other):
+
+		"""Stack two :class:`Dataset` instances together by
+		joining at the column level, and return a new
+		combined ``Dataset`` instance. Requires headers
+		to be set."""
+
+		if not isinstance(other, Dataset):
+			return
+
+		if not self.headers or not other.headers:
+			raise HeadersNeeded
+
+		if self.height != other.height:
+			raise InvalidDimensions
+
+		new_headers = self.headers + other.headers
+
+		_dset = Dataset()
+
+		for column in self.headers:
+			_dset.append(col=self[column])
+
+		for column in other.headers:
+			_dset.append(col=other[column])
+
+		_dset.headers = new_headers
+
+		return _dset
 
 	def wipe(self):
 		"""Removes all content and headers from the :class:`Dataset` object."""

test_tablib.py

@@ -364,7 +364,44 @@ class TablibTestCase(unittest.TestCase):
 				   ("last_name","Adams", "Washington", "Jefferson"))
 		self.assertEqual(second_row,
 				   ("gpa",90, 67, 50))
+	
+	def test_row_stacking(self):
 
+		"""Row stacking."""
+
+		to_join = tablib.Dataset(headers=self.founders.headers)
+		
+		for row in self.founders:
+			to_join.append(row=row)
+		
+		row_stacked = self.founders.row_stack(to_join)
+
+		for column in row_stacked.headers:
+
+			original_data = self.founders[column]
+			expected_data = original_data + original_data
+			self.assertEqual(row_stacked[column], expected_data)
+
+	def test_column_stacking(self):
+
+		"""Column stacking"""
+
+		to_join = tablib.Dataset(headers=self.founders.headers)
+		
+		for row in self.founders:
+			to_join.append(row=row)
+
+		column_stacked = self.founders.column_stack(to_join)
+
+		for index, row in enumerate(column_stacked):
+
+			original_data = self.founders[index]
+			expected_data = original_data + original_data
+			self.assertEqual(row, expected_data)
+
+		self.assertEqual(column_stacked[0],
+				   ("John", "Adams", 90, "John", "Adams", 90))
+	
 	def test_wipe(self):
 		"""Purge a dataset."""