nocasedict

2.2.0 verified Mon Apr 27 auth: no python

A case-insensitive ordered dictionary for Python. Version 2.2.0, supports Python >=3.9. Released under Apache 2.0. Maintained with irregular releases.

pip install nocasedict

Common errors

error ImportError: No module named 'nocasedict' ↓

cause Library not installed or installed in a different Python environment.

fix

Run: pip install nocasedict

error AttributeError: module 'nocasedict' has no attribute 'NocaseDict' ↓

cause Incorrect import: trying to import from the module but the class is not found due to wrong import statement.

fix

Use: from nocasedict import NocaseDict

error TypeError: 'NocaseDict' object does not support item assignment ↓

cause Accidentally passed a frozen instance or tried to use mappingproxy-like behavior.

fix

Create a new NocaseDict from the frozen one: NocaseDict(frozen_dict)

Warnings

breaking Version 2.0.0 dropped support for Python 2.7 and 3.5. Also changes how keys are stored internally; no more separate lowercase key store. Bulk import may break if using internal attributes. ↓

fix Upgrade to 2.x only if using Python >=3.6. Code relying on __dict__ or internal key storage will break.

deprecated The 'NocaseDict.fromkeys' class method is deprecated since 2.2.0 and will be removed in a future release. ↓

fix Use dict.fromkeys and convert: NocaseDict(dict.fromkeys(keys, value)).

gotcha Equality comparison with regular dict is case-sensitive. NocaseDict('a':1) == {'a':1} is True, but NocaseDict('A':1) == {'a':1} is False. ↓

fix Be aware that case-insensitivity only applies within NocaseDict itself, not when comparing to dict.

gotcha Inheritance from NocaseDict may cause unexpected behavior because it overrides __setitem__ and __getitem__ for case-insensitivity. Custom subclasses must carefully call super(). ↓

fix Ensure you override all relevant methods and call super().__setitem__ with the intended key.

Imports

NocaseDict
wrong
```
import nocasedict.NocaseDict
```
correct
```
from nocasedict import NocaseDict
```
NocaseDict is a top-level class, not a module.

Quickstart

Create a case-insensitive dictionary and access keys case-insensitively.

from nocasedict import NocaseDict

d = NocaseDict({'KEY': 'value'})
print(d['key'])  # 'value'
print(d['KEY'])  # 'value'
d['NewKey'] = 1
print('newkey' in d)  # True