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4 Layers of AWS Architecture a Quick Answer

I have collected real interview questions on AWS key architecture components. Those are S3, EC2, SQS, and SimpleDB. AWS is one of the most popular skills in the area of Cloud computing. Many companies are recruiting software developers to work on cloud computing.

AWS Key Architecture Components AWS is the top cloud platform. The knowledge of this helpful to learn other cloud platforms. Below are the questions asked in interviews recently.
What are the components involved in AWS?Amazon S3.With this, one can retrieve the key information which is occupied in creating cloud structural design, and the amount of produced information also can be stored in this component that is the consequence of the key specified.Amazon EC2. Helpful to run a large distributed system on the Hadoop cluster. Automatic parallelization and job scheduling can be achieved by this component.Amazon SQS. This component acts as a mediator between different controllers. Also worn for cushioning requirements those are obt…

Python Dictionary Vs List With Examples

Dictionary and List we use interchangeably in Python to store values. For beginners, both look the same. In reality, they both differ. I want to share some key differences between Python Dictionary and List.

Python Dictionary Vs List Both Not The Same Why

Python Dictionary Vs List Top Differences.


Values in lists are accessed by means of integers called indices, which indicate where in the list a given value is found.

Dictionaries access values by means of integers, strings, or other Python objects called keys, which indicate where in the dictionary a given value is found. 

  • In other words, both lists and dictionaries provide indexed access to arbitrary values, but the set of items that can be used as dictionary indices is much larger than, and contains, the set of items that can be used as list indices. 
  • Also, the mechanism that dictionaries use to provide indexed access is quite different from that used by lists.
  • Both lists and dictionaries can store objects of any type.
  • Values stored in a list are implicitly ordered by their positions in the list because the indices that access these values are consecutive integers. You may or may not care about this ordering, but you can use it if desired. 
  • Values stored in a dictionary are not implicitly ordered relative to one another because dictionary keys aren’t just numbers. 


Note that if you’re using a dictionary but also care about the order of the items (the order in which they were added, that is), you can use an ordered dictionary, which is a dictionary subclass that can be imported from the collections module.


You can also define an order on the items in a dictionary by using another data structure (often a list) to store such an ordering explicitly; this won’t change the fact that basic dictionaries have no implicit (built-in) ordering.

Examples That Show The Differences Between Dictionary and List.


How to Use List and Dictionary.


In spite of the differences between them, the use of dictionaries and lists often appears to be the same.


As a start, an empty dictionary is created much like an empty list, but with curly braces instead of square brackets:

>>> x = []
>>> y = {}

Here, the first line creates a new, empty list and assigns it to x. The second line creates a new, empty dictionary and assigns it to y.


How to Assign Values Dictionary and List.


After you create a dictionary, you may store values in it as though it were a list:

>>> y[0] = 'Hello'
>>> y[1] = 'Goodbye'

Even in these assignments, there’s already a significant operational difference between the dictionary and list usage.


Trying to do the same thing with a list would result in an error because, in Python, it’s illegal to assign to a position in a list that doesn’t exist. For example, if you try to assign to the 0th element of the list x, you receive an error:

>>> x[0] = 'Hello'
Traceback (innermost last):
  File "<stdin>", line 1, in ?
IndexError: list assignment index out of range


This isn’t a problem with dictionaries; new positions in dictionaries are created as necessary. Having stored some values in the dictionary, now you can access and use them:

>>> print(y[0])
Hello

>>> y[1] + ", Friend."
'Goodbye, Friend.'

All in all, this makes a dictionary look pretty much like a list. Now for the big difference. Store (and use) some values under keys that aren’t integers:

>>> y["two"] = 2
>>> y["pi"] = 3.14
>>> y["two"] * y["pi"]

This is definitely something that can’t be done with lists! Whereas list indices must be integers, dictionary keys are much less restricted; they may be numbers, strings, or one of a wide range of other Python objects.


References.

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