Feature/24 pandas plugin

rows/__init__.py

@@ -58,5 +58,9 @@
 except ImportError:
     pass
 
+try:
+    from rows.plugins._pandas import import_from_pandas, export_to_pandas
+except ImportError:
+    pass
 
 __version__ = '0.2.0-dev'

rows/plugins/_pandas.py

@@ -0,0 +1,60 @@
+# coding: utf-8
+
+# Copyright 2014-2015 Álvaro Justen <https://github.com/turicas/rows/>
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License as published by
+#    the Free Software Foundation, either version 3 of the License, or
+#    (at your option) any later version.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import datetime
+
+import pandas
+
+from rows.plugins.utils import create_table
+
+DATE_FORMAT = "%Y-%m-%d %H:%M:%S"
+
+def import_from_pandas(data_frame, *args, **kwargs):
+    meta = {'imported_from': 'pandas', 'filename': 'DataFrame', }
+    return create_table(_dataframe_generator(data_frame), meta=meta, *args,
+                        **kwargs)
+
+def _dataframe_generator(data_frame):
+    yield list(data_frame)
+
+    for _, row in data_frame.iterrows():
+        yield dataframe_row_to_list(row)
+
+def dataframe_row_to_list(row):
+    result = []
+    for element_index, element in enumerate(row):
+        #Problem importing pandas.tslib.Timestamp or pandas.Timestamp
+        if isinstance(element, pandas.tslib.Timestamp):
+            date_string = element.strftime(DATE_FORMAT)
+            if date_string.endswith("00:00:00"):
+                value = datetime.datetime.strptime(date_string,
+                                                   DATE_FORMAT).date()
+            else:
+                value = element.to_datetime()
+        result.append(value)
+    return result
+
+
+def export_to_pandas(table_obj):
+    data_frame = pandas.DataFrame(_generator_table(table_obj),
+                                  columns=table_obj.field_names)
+
+    return data_frame
+
+def _generator_table(table_obj):
+    for row in table_obj:
+        yield list(row)

setup.py

@@ -24,7 +24,8 @@
         'html': ['lxml'], # apt: libxslt-dev libxml2-dev
         'ods': ['lxml'],
         'xls': ['xlrd', 'xlwt'],
-        'xlsx': ['openpyxl'], }
+        'xlsx': ['openpyxl'],
+        'pandas': ['pandas'], }
 EXTRA_REQUIREMENTS['all'] = sum(EXTRA_REQUIREMENTS.values(), [])
 INSTALL_REQUIREMENTS = EXTRA_REQUIREMENTS['csv']
 LONG_DESCRIPTION = '''

tests/tests_plugin_pandas.py

@@ -0,0 +1,56 @@
+# coding: utf-8
+
+# Copyright 2014-2015 Álvaro Justen <https://github.com/turicas/rows/>
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License as published by
+#    the Free Software Foundation, either version 3 of the License, or
+#    (at your option) any later version.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+import unittest
+import mock
+
+import pandas
+
+import rows.plugins._pandas
+import rows.plugins.csv
+import utils
+
+class PluginPandasTestCase(utils.RowsTestMixIn, unittest.TestCase):
+
+    plugin_name = 'pandas'
+    data_frame = pandas.DataFrame([[1, 2, 3, 4], [5, 6, 7, 8]],
+                                  columns=['A', 'B', 'C', 'D'])
+
+    def test_imports(self):
+        self.assertIs(rows.import_from_pandas,
+                rows.plugins._pandas.import_from_pandas)
+
+    @mock.patch('rows.plugins._pandas.create_table')
+    def test_import_from_pandas_uses_create_table(self, mocked_create_table):
+        mocked_create_table.return_value = 101
+        kwargs = {'encoding': 'test', 'some_key': 123, 'other': 456, }
+        result = rows.import_from_pandas(self.data_frame, **kwargs)
+        self.assertTrue(mocked_create_table.called)
+        self.assertEqual(mocked_create_table.call_count, 1)
+        self.assertEqual(result, 101)
+
+        call = mocked_create_table.call_args
+        kwargs['meta'] = {'imported_from': 'pandas', 'filename': 'DataFrame'}
+        self.assertEqual(call[1], kwargs)
+
+    @mock.patch('rows.plugins._pandas.pandas.DataFrame')
+    def test_export_to_pandas_uses_data_frame(self, mocked_data_frame):
+        mocked_data_frame.return_value = 101
+        result = rows.plugins._pandas.export_to_pandas(utils.table)
+        self.assertTrue(mocked_data_frame.called)
+        self.assertTrue(mocked_data_frame.call_count, 1)
+        self.assertEqual(result, 101)
+