Dictionaries are an unordered collection of items. Each item in a dictionary is stored as a key-value pair, where each key is unique and associated with a corresponding value. Dictionaries are mutable, meaning they can be modified after creation.

Basics of Dictionaries

In Python, dictionaries are defined by using curly braces {}' and key-value pairs separated by colons ':'.

For example:

You can access the value associated with a specific key using square brackets ‘[ ]’:

Dictionary’s Capabilities & Limitations

Mutablility : We can add a new key, modify value or delete key-value pairs:

Duplicates Not Allowed: Dictionaries cannot have two items with the same key:

When defining a dictionary, if a key is duplicated, the latest occurrence will overrides the previous one.

Allows Different Data Types: Dictionaries allows define different typed key-value pairs.

Dict Constructor : The dict() constructor provides make a dictionary by args.

Non Restricted Values : There is no restriction on dictionaries values. You can define same values for different keys or you can define any dataype.

Built-in Dictionary Methods

  • dict.clear(): Clears ditionary object’s memory and resets.
  • dict.get(“key” [,”default”]): Searchs related key and returns, if there is not exists related key returns None or defined value
  • dict.keys(): Returns a list of all the keys in the dictionary.
  • dict.values(): Returns a list of all the values in the dictionary.
  • dict.items(): This method returns a list of key-value tuple pairs.
  • dict.pop(“key”): Removes and returns the value associated with the specified key. If the key is not found, it returns the specified default value (or raises a KeyError if not specified).
  • dict.update(new_data: dict) : Updates the dictionary with the key-value pairs from the specified iterable (such as another dictionary or a list of tuples).


In Python, dictionary data types are versatile data structures that enable store data and manipulation data through key-value pairs. Dictionaries offers a flexible and dynamic way to organize and work with data, allowing for quick lookups based on unique keys. With built-in methods and operations, dictionaries facilitate various data processing tasks, making them invaluable tools in Python programming. Whether handling configurations, representing relationships, or managing data, dictionaries provide a convenient and powerful solution for a wide range of applications.

ibrahim tunc
ibrahim tunc
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