Refactor Long Try-except Chain

I have a feeling that this sequence might be written shorter: dim = Dimension.objects.get(pk=rows['pk']) try: dim.name = rows['name'] except KeyError: pass try: dim.ext

Solution 1:

Use the dict.get() method:

dim.name = rows.get('name', dim.name)

Or, for more DRY solution, put all assignments into the loop:

for field_name in ('name', 'external_flg', 'ext_owner', 'ext_table_name',
                   'ext_start_date_column_name', 'ext_end_date_column_name'):
    if field_name inrows:
        setattr(dim, field_name, rows[field_name])

To handle the list data you can make the similar loop:

for i, field_name inenumerate(('name', 'external_flg', 'ext_owner',
                                'ext_table_name', 'ext_start_date_column_name',
                                'ext_end_date_column_name')):
    if i < len[rows]:
        setattr(dim, field_name, rows[i])

Solution 2:

Something like this should work — this answer includes try/catch block to catch KeyError :-)

attributes = ['name', 'external_flg', 'ext_owner', 'ext_table_name',
               'ext_start_date_column_name', 'ext_end_date_column_name']

dim = Dimension.objects.get(pk=rows['pk'])

for attr in attributes:
    try:
        setattr(dim, attr, rows[attr])
    except KeyError:
        pass