Collections Module Deep Dive

Introduction

Overview of all specialized container types in the collections module.

Container Types Summary

Type	Description	Use Case
`namedtuple`	Tuple with named fields	Lightweight objects
`deque`	Double-ended queue	Fast append/pop
`ChainMap`	Multiple dicts as one	Config lookup
`Counter`	Dict for counting	Frequency analysis
`OrderedDict`	Dict preserving order	Legacy Python < 3.7
`defaultdict`	Dict with defaults	Grouping data
`UserDict`	Dict wrapper	Custom dict behavior
`UserList`	List wrapper	Custom list behavior
`UserString`	String wrapper	Custom string behavior

UserDict Example

from collections import UserDict

class CaseInsensitiveDict(UserDict):
    def __setitem__(self, key, value):
        self.data[key.lower()] = value
    
    def __getitem__(self, key):
        return self.data[key.lower()]

Practice Problems

Implement custom collection type
Create case-insensitive dictionary
Build LRU cache from OrderedDict
Extend UserList with validation
Implement string collection with methods

Collections Module Deep Dive

Introduction

Container Types Summary

UserDict Example

Practice Problems

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