Ah, yes. I see the complexity now. Perhaps its worth pulling it all together into two distinct statements after all.

For the record, my approach would be:

```
>>> summary = '{name} ({unit})'.format(name=self.name() or 'unknown', unit=self.units)
>>> '{summary!s:{length}} ({dimension})'.format(length=30, summary=summary, dimension=dimension_header)
'std name (meter)               (x: 10; y: 20;)'
```

It should not be necessary to call the ```str``` function directly.