> For the complete documentation index, see [llms.txt](https://openai.gitbook.io/code-cheatsheets/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://openai.gitbook.io/code-cheatsheets/all/python/collections/fancydicts.md).

# fancyDicts

### OrderedDict

keeps order of insertion

```python
from collections import OrderedDict
```

### DefaultDict

Creates default, nonnull value for keys

```python
from collections import defaultdict
d = defaultdict(list)
for k, v in somePairs:
    d[k].append(v)
```

### Counter

Counts elements

```python
from collections import Counter
c = Counter("hell") #Counter({'l': 2, 'h': 1, 'e': 1})

#Add iterables of values
c.update([1, 3, 4])
c.most_common(10) # 10 most common
```