def test_pairs(self):
        data = {'birthdt': ['08jan2009', '20dec2008', '30dec2008', '21dec2008',
                            '11jan2009'],
                'birthwt': [1766, 3301, 1454, 3139, 4133],
                'id': [101, 102, 103, 104, 105],
                'sex': ['Male', 'Female', 'Female', 'Female', 'Female'],
                'visitdt1': ['11jan2009', '22dec2008', '04jan2009',
                             '29dec2008', '20jan2009'],
                'visitdt2':
                ['21jan2009', nan, '22jan2009', '31dec2008', '03feb2009'],
                'visitdt3': ['05feb2009', nan, nan, '02jan2009', '15feb2009'],
                'wt1': [1823, 3338, 1549, 3298, 4306],
                'wt2': [2011.0, nan, 1892.0, 3338.0, 4575.0],
                'wt3': [2293.0, nan, nan, 3377.0, 4805.0]}

        df = DataFrame(data)

        spec = {'visitdt': ['visitdt%d' % i for i in range(1, 4)],
                'wt': ['wt%d' % i for i in range(1, 4)]}
        result = lreshape(df, spec)

        exp_data = {'birthdt':
                    ['08jan2009', '20dec2008', '30dec2008', '21dec2008',
                     '11jan2009', '08jan2009', '30dec2008', '21dec2008',
                     '11jan2009', '08jan2009', '21dec2008', '11jan2009'],
                    'birthwt': [1766, 3301, 1454, 3139, 4133, 1766, 1454, 3139,
                                4133, 1766, 3139, 4133],
                    'id': [101, 102, 103, 104, 105, 101, 103, 104, 105, 101,
                           104, 105],
                    'sex': ['Male', 'Female', 'Female', 'Female', 'Female',
                            'Male', 'Female', 'Female', 'Female', 'Male',
                            'Female', 'Female'],
                    'visitdt': ['11jan2009', '22dec2008', '04jan2009',
                                '29dec2008', '20jan2009', '21jan2009',
                                '22jan2009', '31dec2008', '03feb2009',
                                '05feb2009', '02jan2009', '15feb2009'],
                    'wt': [1823.0, 3338.0, 1549.0, 3298.0, 4306.0, 2011.0,
                           1892.0, 3338.0, 4575.0, 2293.0, 3377.0, 4805.0]}
        exp = DataFrame(exp_data, columns=result.columns)
        tm.assert_frame_equal(result, exp)

        result = lreshape(df, spec, dropna=False)
        exp_data = {'birthdt':
                    ['08jan2009', '20dec2008', '30dec2008', '21dec2008',
                     '11jan2009', '08jan2009', '20dec2008', '30dec2008',
                     '21dec2008', '11jan2009', '08jan2009', '20dec2008',
                     '30dec2008', '21dec2008', '11jan2009'],
                    'birthwt': [1766, 3301, 1454, 3139, 4133, 1766, 3301, 1454,
                                3139, 4133, 1766, 3301, 1454, 3139, 4133],
                    'id': [101, 102, 103, 104, 105, 101, 102, 103, 104, 105,
                           101, 102, 103, 104, 105],
                    'sex': ['Male', 'Female', 'Female', 'Female', 'Female',
                            'Male', 'Female', 'Female', 'Female', 'Female',
                            'Male', 'Female', 'Female', 'Female', 'Female'],
                    'visitdt': ['11jan2009', '22dec2008', '04jan2009',
                                '29dec2008', '20jan2009', '21jan2009', nan,
                                '22jan2009', '31dec2008', '03feb2009',
                                '05feb2009', nan, nan, '02jan2009',
                                '15feb2009'],
                    'wt': [1823.0, 3338.0, 1549.0, 3298.0, 4306.0, 2011.0, nan,
                           1892.0, 3338.0, 4575.0, 2293.0, nan, nan, 3377.0,
                           4805.0]}
        exp = DataFrame(exp_data, columns=result.columns)
        tm.assert_frame_equal(result, exp)

        spec = {'visitdt': ['visitdt%d' % i for i in range(1, 3)],
                'wt': ['wt%d' % i for i in range(1, 4)]}
        self.assertRaises(ValueError, lreshape, df, spec)
dataset/ETHPy150Open pydata/pandas/pandas/tests/test_reshape.py/TestLreshape.test_pairs/original