Namedtuple in Python
Python supports a type of container dictionaries called “namedtuple()” present in the module, “collections“. Like dictionaries, they contain keys that are hashed to a particular value. But on contrary, it supports both access from key-value and iteration, the functionality that dictionaries lack.
The Student age using index is : 19 The Student name using keyname is : Nandini
Let’s see various Operations on namedtuple()
- Access by index: The attribute values of namedtuple() are ordered and can be accessed using the index number unlike dictionaries which are not accessible by index.
- Access by keyname: Access by keyname is also allowed as in dictionaries.
- using getattr(): This is yet another way to access the value by giving namedtuple and key value as its argument.
The Student age using index is : 19 The Student name using keyname is : Nandini The Student DOB using getattr() is : 2541997
- _make() :- This function is used to return a namedtuple() from the iterable passed as argument.
- _asdict() :- This function returns the OrderedDict() as constructed from the mapped values of namedtuple().
- using “**” (double star) operator :- This function is used to convert a dictionary into the namedtuple().
The namedtuple instance using iterable is : Student(name='Manjeet', age='19', DOB='411997') The OrderedDict instance using namedtuple is : OrderedDict([('name', 'Nandini'), ('age', '19'), ('DOB', '2541997')]) The namedtuple instance from dict is : Student(name='Nikhil', age=19, DOB='1391997')
- _fields: This function is used to return all the keynames of the namespace declared.
- _replace(): _replace() is like str.replace() but targets named fields( does not modify the original values)
All the fields of students are : ('name', 'age', 'DOB') returns a new namedtuple : Student(name='Manjeet', age='19', DOB='2541997') Student(name='Nandini', age='19', DOB='2541997')
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Using the collections module:
This approach creates a new namedtuple class using the namedtuple() function from the collections module. The first argument is the name of the new class, and the second argument is a list of field names.
The code defines a named tuple called Point with two fields x and y. An instance of the Point class is then created with x=1 and y=2, and its x and y attributes are printed.
The time complexity of accessing an attribute of a named tuple is O(1), because it is a simple attribute lookup. Therefore, the time complexity of printing p.x and p.y is O(1) each.
The space complexity of the code is O(1) because it does not allocate any additional memory beyond what is required for the named tuple instance p and the Point class definition.
Overall, the code has a constant time and space complexity.
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