What is python dictionary explain with example?
Python dictionary is an ordered collection (starting from Python 3.7) of items. Each item of a dictionary has a Show
Dictionaries are optimized to retrieve values when the key is known. Creating Python DictionaryCreating a dictionary is as simple as placing items inside curly braces An item has a While the values can be of any data type and can repeat, keys must be of immutable type (string, number or tuple with immutable elements) and must be unique.
As you can see from above, we can also create a dictionary using the built-in
Accessing Elements from DictionaryWhile indexing is used with other data types to access values, a dictionary uses If we use the square brackets
Output Jack 26 None Traceback (most recent call last): File " Changing and Adding Dictionary elementsDictionaries are mutable. We can add new items or change the value of existing items using an assignment operator. If the key is already present, then the existing value gets updated. In case the key is not present, a new (key: value) pair is added to the dictionary.
Output {'name': 'Jack', 'age': 27} {'name': 'Jack', 'age': 27, 'address': 'Downtown'} Removing elements from DictionaryWe can remove a
particular item in a dictionary by using the The We can also use the
Output 16 {1: 1, 2: 4, 3: 9, 5: 25} (5, 25) {1: 1, 2: 4, 3: 9} {} Traceback (most recent call last): File " Python Dictionary MethodsMethods that are available with a dictionary are tabulated below. Some of them have already been used in the above examples.
Here are a few example use cases of these methods.
Output {'Math': 0, 'English': 0, 'Science': 0} ('Math', 0) ('English', 0) ('Science', 0) ['English', 'Math', 'Science'] Python Dictionary ComprehensionDictionary comprehension is an elegant and concise way to create a new dictionary from an iterable in Python. Dictionary comprehension consists of an expression pair (key: value) followed by a Here is an example to make a dictionary with each item being a pair of a number and its square.
Output {0: 0, 1: 1, 2: 4, 3: 9, 4: 16, 5: 25} This code is equivalent to
Output {0: 0, 1: 1, 2: 4, 3: 9, 4: 16, 5: 25} A dictionary comprehension can optionally contain more for or if statements. An optional Here are some examples to make a dictionary with only odd items.
Output {1: 1, 3: 9, 5: 25, 7: 49, 9: 81} To learn more dictionary comprehensions, visit Python Dictionary Comprehension. Other Dictionary OperationsDictionary Membership TestWe can test if a
Output True True False Iterating Through a DictionaryWe can iterate through each key in a dictionary using a
Output 1 9 25 49 81 Dictionary Built-in FunctionsBuilt-in functions like
Here are some examples that use built-in functions to work with a dictionary.
Output False True 6 [0, 1, 3, 5, 7, 9] What's a Python dictionary?Dictionaries in Python
Dictionaries are Python's implementation of a data structure that is more generally known as an associative array. A dictionary consists of a collection of key-value pairs. Each key-value pair maps the key to its associated value.
What is dictionary data type with example?Represents an unordered collection of keys and values. The Dictionary data type is optimized for fast lookup of values.
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In this article.. What is dictionary explain Python dictionaries in detail discussing its operations?Python Dictionary is used to store the data in a key-value pair format. The dictionary is the data type in Python, which can simulate the real-life data arrangement where some specific value exists for some particular key. It is the mutable data-structure. The dictionary is defined into element Keys and values.
What is the syntax of dictionary in Python?Syntax for Python Dictionary
Dictionary is listed in curly brackets, inside these curly brackets, keys and values are declared. Each key is separated from its value by a colon (:), while commas separate each element.
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