[Pytest-commit] Issue #462: What is the correct spelling when using unicode in assertions? (hpk42/pytest)

[Charlie Clark]

New issue 462: What is the correct spelling when using unicode in assertions?
https://bitbucket.org/hpk42/pytest/issue/462/what-is-the-correct-spelling-when-using

Charlie Clark:

I'm really struggling with a way to do this that will work with Python 2 and 3.

I have a simple assertion in a file encoded as UTF-8
` assert ws['A16'].value == '=IF(ISBLANK(B16), "Düsseldorf", B16)'`

Unfortunately, this leads to an unholy failure because pytest seems to be running some internal conversion:


```
#!python

___________________________________________________________ test_read_complex_formulae ____________________________________________________________

    def test_read_complex_formulae():
        null_file = os.path.join(DATADIR, 'reader', 'formulae.xlsx')
        wb = load_workbook(null_file)
        ws = wb.get_active_sheet()
    
        # Test normal forumlae
        assert ws.cell('A1').data_type != 'f'
        assert ws.cell('A2').data_type != 'f'
        assert ws.cell('A3').data_type == 'f'
        assert 'A3' not in ws.formula_attributes
        assert ws.cell('A3').value == '=12345'
        assert ws.cell('A4').data_type == 'f'
        assert 'A4' not in ws.formula_attributes
        assert ws.cell('A4').value == '=A2+A3'
        assert ws.cell('A5').data_type == 'f'
        assert 'A5' not in ws.formula_attributes
        assert ws.cell('A5').value == '=SUM(A2:A4)'
    
    
        # Test unicode
>       assert ws['A16'].value == '=IF(ISBLANK(B16), "Düsseldorf", B16)'

null_file  = '/Users/charlieclark/Projects/openpyxl/openpyxl/tests/test_data/reader/formulae.xlsx'
wb         = <openpyxl.workbook.Workbook object at 0x107773110>
ws         = <Worksheet "Sheet1">

openpyxl/tests/test_read.py:261: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

ops = ('==',), results = (False,), expls = ('%(py3)s\n{%(py3)s = %(py1)s.value\n} == %(py6)s',)
each_obj = ('=IF(ISBLANK(B16), "Düsseldorf", B16)', '=IF(ISBLANK(B16), "D\xc3\xbcsseldorf", B16)')

    def _call_reprcompare(ops, results, expls, each_obj):
        for i, res, expl in zip(range(len(ops)), results, expls):
            try:
                done = not res
            except Exception:
                done = True
            if done:
                break
        if util._reprcompare is not None:
>           custom = util._reprcompare(ops[i], each_obj[i], each_obj[i + 1])

done       = True
each_obj   = ('=IF(ISBLANK(B16), "Düsseldorf", B16)', '=IF(ISBLANK(B16), "D\xc3\xbcsseldorf", B16)')
expl       = '%(py3)s\n{%(py3)s = %(py1)s.value\n} == %(py6)s'
expls      = ('%(py3)s\n{%(py3)s = %(py1)s.value\n} == %(py6)s',)
i          = 0
ops        = ('==',)
res        = False
results    = (False,)

lib/python2.7/site-packages/_pytest/assertion/rewrite.py:343: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

op = '==', left = '=IF(ISBLANK(B16), "Düsseldorf", B16)', right = '=IF(ISBLANK(B16), "D\xc3\xbcsseldorf", B16)'

    def callbinrepr(op, left, right):
        hook_result = item.ihook.pytest_assertrepr_compare(
            config=item.config, op=op, left=left, right=right)
    
        for new_expl in hook_result:
            if new_expl:
                # Don't include pageloads of data unless we are very
                # verbose (-vv)
>               if (len(py.builtin._totext('').join(new_expl[1:])) > 80*8
                        and item.config.option.verbose < 2):
E                       UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 22: ordinal not in range(128)

hook_result = [['\'=IF(ISBLANK(...eldorf", B16)\' == \'=IF(ISBLANK(B...eldorf", B16)\'', '- =IF(ISBLANK(B16), "Düsseldorf", B16)', '?                     ^', '+ =IF(ISBLANK(B16), "D\xc3\xbcsseldorf", B16)', '?                     ^^']]
item       = <Function 'test_read_complex_formulae'>
left       = '=IF(ISBLANK(B16), "Düsseldorf", B16)'
new_expl   = ['\'=IF(ISBLANK(...eldorf", B16)\' == \'=IF(ISBLANK(B...eldorf", B16)\'', '- =IF(ISBLANK(B16), "Düsseldorf", B16)', '?                     ^', '+ =IF(ISBLANK(B16), "D\xc3\xbcsseldorf", B16)', '?                     ^^']
op         = '=='
right      = '=IF(ISBLANK(B16), "D\xc3\xbcsseldorf", B16)'

lib/python2.7/site-packages/_pytest/assertion/__init__.py:83: UnicodeDecodeError
----------------------------------------------------------------- Captured stderr -----------------------------------------------------------------
/Users/charlieclark/Projects/openpyxl/openpyxl/tests/test_read.py:261: UnicodeWarning: Unicode equal comparison failed to convert both arguments to Unicode - interpreting them as being unequal
  assert ws['A16'].value == '=IF(ISBLANK(B16), "Düsseldorf", B16)'
/Users/charlieclark/Projects/openpyxl/lib/python2.7/site-packages/_pytest/assertion/util.py:178: UnicodeWarning: Unicode unequal comparison failed to convert both arguments to Unicode - interpreting them as being unequal
  if left[i] != right[i]:
/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/difflib.py:439: UnicodeWarning: Unicode equal comparison failed to convert both arguments to Unicode - interpreting them as being unequal
  a[besti+bestsize] == b[bestj+bestsize]:
/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/difflib.py:978: UnicodeWarning: Unicode equal comparison failed to convert both arguments to Unicode - interpreting them as being unequal
  if ai == bj:
/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/difflib.py:435: UnicodeWarning: Unicode equal comparison failed to convert both arguments to Unicode - interpreting them as being unequal
  a[besti-1] == b[bestj-1]:

```
I've seen similar issues reported but nothing telling me the correct way to write the test.