Does everyone use #Python's `object()` for unique tokens? Like:

```
no_match = object()

val = some_dict.get('key', no_match)

if val is not no_match:

do_something()
```

I don't know what else `object()` would be used for (and why they'd keep it).

@2ck
In Python, 'object' is the common base class of all classes.

Anyhow, I would use either:
if 'key' in some_dict: …
if only existence is of interest
or
class no_match: pass
if value will be actually used (no need to instantiate an object) anyhow, rethinking: for the later, your way might be more efficient, I need to time it

@kirschwipfel i use the pattern in the OP for mappings where the cost of lookup is significant (e.g., ZODB BTree), and where the standard "not found" value of None is a legitimate value to store, and I need to know it was stored. it's come up in a couple situations