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Python is a magical language with many ideas that even superior customers might not be acquainted with. Dunder or Magical strategies is one among them. Magic strategies are particular strategies which are surrounded by double underscores. They don’t seem to be referred to as explicitly not like the bizarre strategies in python. One such magic technique is the __getitem__ technique, enabling the Python objects to behave like sequences or containers e.g lists, dictionaries, and tuples. It takes the index or slice and retrieves its related worth from the gathering. It’s invoked routinely at any time when we use the indexer [ ] operator to entry the weather inside your object.
Consider this technique as a magic wand that grants you the facility to extract the required info simply by writing a number of traces of code. Fascinating proper? This technique can be used extensively in information evaluation and machine studying. So, let’s dive deeper into the __getitem__ technique and uncover its energy and adaptability.
I would like you to know that your obligation as a Python programmer is extra than simply writing practical code. Your code needs to be environment friendly, readable, and maintainable. Utilizing __getitem__ will enable you obtain these objectives. Listed below are another advantages of utilizing this magic technique:
Reduces reminiscence utilization by permitting you to extract solely the important info as a substitute of loading the whole information construction into the reminiscence
Offers larger flexibility in how the info is dealt with and manipulated
Permits you to iterate over the gathering with out looping over the info
Enhances the performance by permitting you to write down superior indexing that might not be potential with the built-in varieties
Simplifies the code because it makes use of the acquainted notation
The syntax for the __getitem__ technique is as follows:
# Your Implementation
move
It defines the habits of the perform and takes the index that you’re making an attempt to entry in its parameter. We are able to use this technique like this:
This interprets to the assertion my_obj.__getitem__(index) beneath the hood. Now you would possibly assume that how is it totally different from the built-in indexer [] operator? Wherever you utilize this notation, python routinely calls the __getitem__ technique for you and is the shorthand for accessing parts. However if you wish to change the habits of indexing for customized objects, it is advisable to explicitly name the __getitem__ technique.
Instance #01
Allow us to begin with a straightforward instance first. We’ll create a Scholar class that can have the checklist of all the scholars and we are able to entry them by index and take into account that the index represents their distinctive pupil ID.
def __init__(self, names):
self.names=names
def __getitem__(self,index):
return self.names[index]
section_A= Scholar([“David”, “Elsa”, “Qasim”])
print(section_A[2])
Output:
Now we’ll transfer over to a complicated instance the place we’ll change the indexing habits utilizing the __getitem__ technique. Suppose that I’ve a listing of string parts and I need to retrieve the factor at any time when I enter its index place and I may also get the index place if I enter the string itself.
def __init__(self, objects):
self.objects = objects
def __getitem__(self, index):
if isinstance(index, int):
return self.objects[index]
elif isinstance(index, str):
return self.objects.index(index)
else:
increase TypeError(“Invalid Argument Sort”)
my_list = MyList([‘red’, ‘blue’, ‘green’, ‘black’])
# Indexing with integer keys
print(my_list[0])
print(my_list[2])
# Indexing with string keys
print(my_list[‘red’])
print(my_list[‘green’])
Output:
This technique is extraordinarily helpful for the short lookup of the occasion attributes. Contemplating the flexibleness and flexibility of this technique, I’d say this is among the most underutilized magic strategies of Python. I hope you loved studying this text and do let me know within the remark part in case you are to know in regards to the different magic strategies in Python. Kanwal Mehreen is an aspiring software program developer with a eager curiosity in information science and purposes of AI in drugs. Kanwal was chosen because the Google Technology Scholar 2022 for the APAC area. Kanwal likes to share technical information by writing articles on trending matters, and is captivated with enhancing the illustration of ladies in tech business.
