Merge branch 'feature/stacking' into develop

tablib/core.py

@@ -548,6 +548,63 @@ class Dataset(object):
 
 		return _dset
 
+
+	def stack_rows(self, other):
+		"""Stack two :class:`Dataset` instances together by
+		joining at the row level, and return 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 stack_columns(self, other):
+		"""Stack two :class:`Dataset` instances together by
+		joining at the column level, and return a new
+		combined ``Dataset`` instance. If either ``Dataset``
+		has headers set, than the other must as well."""
+
+		if not isinstance(other, Dataset):
+			return
+
+		if self.headers or other.headers:
+			if not self.headers or not other.headers:
+				raise HeadersNeeded
+
+		if self.height != other.height:
+			raise InvalidDimensions
+
+		try:
+			new_headers = self.headers + other.headers
+		except TypeError:
+			new_headers = None
+
+		_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."""
 		self._data = list()

test_tablib.py

@@ -194,7 +194,7 @@ class TablibTestCase(unittest.TestCase):
 		data.tsv
 		data.xls
 
- 
+
 	def test_book_export_no_exceptions(self):
 		"""Test that varoius exports don't error out."""
 
@@ -245,7 +245,7 @@ class TablibTestCase(unittest.TestCase):
 
 		self.assertEqual(_yaml, data.yaml)
 
-		
+
 	def test_yaml_import_book(self):
 		"""Generate and import YAML book serialization."""
 		data.append(self.john)
@@ -258,7 +258,7 @@ class TablibTestCase(unittest.TestCase):
 		book.yaml = _yaml
 
 		self.assertEqual(_yaml, book.yaml)
-		
+
 
 	def test_csv_import_set(self):
 		"""Generate and import CSV set serialization."""
@@ -286,7 +286,7 @@ class TablibTestCase(unittest.TestCase):
 
 	def test_csv_format_detect(self):
 		"""Test CSV format detection."""
-		
+
 		_csv = (
 			'1,2,3\n'
 			'4,5,6\n'
@@ -295,13 +295,13 @@ class TablibTestCase(unittest.TestCase):
 		_bunk = (
 			'¡¡¡¡¡¡¡¡£™∞¢£§∞§¶•¶ª∞¶•ªº••ª–º§•†•§º¶•†¥ª–º•§ƒø¥¨©πƒø†ˆ¥ç©¨√øˆ¥≈†ƒ¥ç©ø¨çˆ¥ƒçø¶'
 		)
-		
+
 		self.assertTrue(tablib.formats.csv.detect(_csv))
 		self.assertFalse(tablib.formats.csv.detect(_bunk))
 
 	def test_tsv_format_detect(self):
 		"""Test TSV format detection."""
-		
+
 		_tsv = (
 			'1\t2\t3\n'
 			'4\t5\t6\n'
@@ -310,7 +310,7 @@ class TablibTestCase(unittest.TestCase):
 		_bunk = (
 			'¡¡¡¡¡¡¡¡£™∞¢£§∞§¶•¶ª∞¶•ªº••ª–º§•†•§º¶•†¥ª–º•§ƒø¥¨©πƒø†ˆ¥ç©¨√øˆ¥≈†ƒ¥ç©ø¨çˆ¥ƒçø¶'
 		)
-		
+
 		self.assertTrue(tablib.formats.tsv.detect(_tsv))
 		self.assertFalse(tablib.formats.tsv.detect(_bunk))
 
@@ -357,7 +357,7 @@ class TablibTestCase(unittest.TestCase):
 		transposed_founders = self.founders.transpose()
 		first_row = transposed_founders[0]
 		second_row = transposed_founders[1]
-		
+
 		self.assertEqual(transposed_founders.headers,
 				  ["first_name","John", "George", "Thomas"])
 		self.assertEqual(first_row,
@@ -365,6 +365,44 @@ class TablibTestCase(unittest.TestCase):
 		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.stack_rows(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.stack_columns(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."""