When to use __getattr__

Question

I came across the `__getattr__` built-in and was wondering when it would be used. I had a hard time thinking of a practical use from the documentation http://docs.python.org/reference/datamodel.html#. What would be an actual example of how it could be used and useful in code?

Accepted Answer

One example is to use object notation with dictionaries. For example, consider a dictionary

```
myDict = {'value': 1}
```

Typically in Python one accesses the 'value' variable as

```
myDict['value']
```

which will print `1` at the Python interpreter. However, one may wish to use the `myDict.value` notation. This may be achieved by using the following class:

```
class DictAsMember(dict):
    def __getattr__(self, name):
        value = self[name]
        if isinstance(value, dict):
            value = DictAsMember(value)
        return value

my_dict = DictAsMember()
my_dict['property'] = {'sub_property': 1}

print(my_dict.property.sub_property) # 1 will be printed
```

When to use getattr

Solution

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