Do basic processing on psycopg2 exceptions to print or map the Diagnostic object

psycopg2_exception.py

def psycopg2_diag_summarize(err: psycopg2.Error, formatted_lines: bool = False) -> Union[Dict, List[str]]:
    """Return a dict representation of a psycopg2.extensions.Diagnostics object

     - Dynamically produce a dict for all public members of the object using dir() to get the
       attribute names
     - Filter out some undesirables (None, callables, non-localized versions of strings)
     - Rename a fixed list of keys to make it more conducive to pretty-printing
    
    Uses f-strings, so needs Python >= 3.6
    psycopg2 started exposing the Diagnostic object some time >= 2.5

    """
    av_map = {name: getattr(err.diag, name, None) for name in dir(err.diag) if not name.startswith('_') and not callable(getattr(err.diag, name))}
    # Filter out None, callables and the "non-localized" version of strings (which are effectively duplicates for us)
    f_map = {k: v for k, v in av_map.items() if v is not None and not callable(v) and not k.endswith('nonlocalized')}
    source_file = f_map.pop('source_file', None)
    source_function = f_map.pop('source_function', None)
    source_line = f_map.pop('source_line', None)
    f_map['Context'] = f_map.pop('context', None)
    f_map['Source'] = f'{source_file}:{source_function}() :: {source_line}'
    f_map['Error Message'] = f_map.pop('message_primary', 'N/A')
    f_map['Error Message Detail'] = f_map.pop('message_detail', 'N/A')
    f_map['SQL State'] = f_map.pop('sqlstate', 'N/A')

    if formatted_lines is True:
        # Return a bunch of lines so they can be called in context from a logger
        lines = [
            f'===== psycopg2.extensions.Diagnostics Report =====',
            f'===== EXCEPTION:  {err.__class__.__name__} =====']
        for key, value in sorted(f_map.items()):
            lines.append( f'   diag.{key:<24} = {value}')
        return lines

    # Return a plain key/value mapping as a dict
    return f_map