How to reverse a String in Python

How To Reverse a String in Python. Learn two methods and find out which is fastest

A string is a sequence of character data. We commonly refer to it as text data. Additionally, strings are iterables, which are enumerables—a data type that can be counted over—that have a structured order as well. Reversing a string means taking the last character and making it the first, second to last becomes second, etc.

Here’s a quick visual example:

name = "Jonathan"

# name in reverse => "nahtanoJ"

So, how do we reverse a string? There are two ways that I’ll cover.

• Programmatically using reverse/join. This is a generic technique that involves creating a reversed iterable and reconstituting it as a string. The exact implementation is Python-specific; however, the technique is broadly implemented across many languages.
• The Pythonic way using slice notation. This is a condensed technique that is more specific to Python as slice notation is not found in all languages.

Technique 1. Reverse/Join

This method involves treating the string as an array of characters, reversing it, and reconstituting it as a string. In other languages, this technique might involve a for loop to iterate over each index and create a reversed data set. The next step is to take the array and recombine it as a string.

Here’s a JavaScript example to show how this looks within a traditional for loop.

var name = "Jonathan";
var arr = [];

for(var i=name.length-1; i >= 0; i--) {
   arr.push(name[i]);
}

var flipped = arr.join("");

console.log(flipped); // nahtanoJ

What we do here is begin at the highest index and manually count down, populating an array with each character. Finally, we join the array with an empty string as a delimiter, meaning the characters are sequential with nothing between them.

In Python, we don’t have traditional for loops. It could be recreated using a while loop, but we’re not going to go that route. Instead, we’ll use the reversed() function to return a reverse iterator that will be similarly joined by empty strings.

name = "Jonathan"

reversed = "".join(reversed(name))

print(reversed) # nahtanoJ

Notice that .join() is a member of the string class in the Python implementation.

Technique 2. Slice Notation

Slice notation is a technique unique to Python that allows a shorthand notation within an iterable’s square brackets, which then executes a traditional slice.

Slice notation involves two colons and up to three values within the square brackets. The first, middle, and end values—separated by colons—are as follows: [start:stop:step]

By omitting the start and stop positions while passing -1 as the step value, we instruct Python to slice counting backwards and not to stop before the end of the string.

name = "Jonathan"

print(name[::-1]) # nahtanoJ

Performance Comparison

According to Dan Bader, slice notation is up to seven times faster than the reverse/join technique!

I replicated his test scenarios and yielded similar, but not as dramatic results.

import timeit

def reverse_join(s):
    return "".join(reversed(s))
		
def slice_notation(s):
    return s[::-1]
		
s = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"

reverse_join_times = timeit.repeat(lambda: reverse_join(s))
slice_notation_times = timeit.repeat(lambda: slice_notation(s))

avg_reverse = sum(reverse_join_times)/len(reverse_join_times)
avg_slice = sum(slice_notation_times)/len(slice_notation_times)

print(avg_reverse) # 1.8536329854000002 
print(avg_slice) # 0.38605856120000015
print(avg_reverse / avg_slice) # 4.801429554206191

Do you have another way of reversing a string? Share it and any other thoughts or insights in the comments below!

Thank you for reading !

#Python #Data Science #Development

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By areas, we mean FinTech, HealthTech, InsureTech, Cybersecurity, and that's just the beginning. These are New Economy areas, and Python has the ability to serve every one of them. The vast majority of them require massive computational abilities. Python's code is dynamic and powerful - equipped for taking care of the heavy traffic and substantial algorithmic capacities. 

Programming advancement is multidimensional today. Endeavor programming requires an intelligent application with AI and ML capacities. Shopper based applications require information examination to convey a superior client experience. Netflix, Trello, and Amazon are genuine instances of such applications. Python assists with building them effortlessly. 

5 Reasons to Utilize Python for Programming Web Apps 

Python can do such numerous things that developers can't discover enough reasons to admire it. Python application development isn't restricted to web and enterprise applications. It is exceptionally adaptable and superb for a wide range of uses.

Robust frameworks 

Python is known for its tools and frameworks. There's a structure for everything. Django is helpful for building web applications, venture applications, logical applications, and mathematical processing. Flask is another web improvement framework with no conditions. 

Web2Py, CherryPy, and Falcon offer incredible capabilities to customize Python development services. A large portion of them are open-source frameworks that allow quick turn of events. 

Simple to read and compose 

Python has an improved sentence structure - one that is like the English language. New engineers for Python can undoubtedly understand where they stand in the development process. The simplicity of composing allows quick application building. 

The motivation behind building Python, as said by its maker Guido Van Rossum, was to empower even beginner engineers to comprehend the programming language. The simple coding likewise permits developers to roll out speedy improvements without getting confused by pointless subtleties. 

Utilized by the best 

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Massive community support 

Python has a steadily developing community that offers enormous help. From amateurs to specialists, there's everybody. There are a lot of instructional exercises, documentation, and guides accessible for Python web development solutions. 

Today, numerous universities start with Python, adding to the quantity of individuals in the community. Frequently, Python designers team up on various tasks and help each other with algorithmic, utilitarian, and application critical thinking. 

Progressive applications 

Python is the greatest supporter of data science, Machine Learning, and Artificial Intelligence at any enterprise software development company. Its utilization cases in cutting edge applications are the most compelling motivation for its prosperity. Python is the second most well known tool after R for data analytics.

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Summary

Thinking about the advances in programming and innovation, Python is a YES for an assorted scope of utilizations. Game development, web application development services, GUI advancement, ML and AI improvement, Enterprise and customer applications - every one of them uses Python to its full potential. 

The disadvantages of Python web improvement arrangements are regularly disregarded by developers and organizations because of the advantages it gives. They focus on quality over speed and performance over blunders. That is the reason it's a good idea to utilize Python for building the applications of the future.

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Let’s get started

Swapping value in Python

Instead of creating a temporary variable to hold the value of the one while swapping, you can do this instead

>>> FirstName = "kalebu"
>>> LastName = "Jordan"
>>> FirstName, LastName = LastName, FirstName 
>>> print(FirstName, LastName)
('Jordan', 'kalebu')

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Intro

In many situations you may find yourself having duplicates files on your disk and but when it comes to tracking and checking them manually it can tedious.

Heres a solution

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But How do we do it?

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The answer is hashing, with hashing can generate a given string of letters and numbers which act as the identity of a given file and if we find any other file with the same identity we gonna delete it.

There’s a variety of hashing algorithms out there such as

• md5
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Python TypeError: Can't Multiply Sequence By Non-int Of Type 'float'

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We get this situation when we take input from user and do computation over it. The inputs are always in string type, no matter if a digit is entered, it will be treated as string. It’s your job to typecast it to your required type like in this case, its float.

#python #python error #python list #python numpy #python string #python-short

Python Strings Tutorial - How To Use Strings In Python

Edureka Python Certification Training: https://www.edureka.co/python-program…
This Edureka video on ‘Python Strings’ will help you understand how we can use Strings in Python with various methods and operations. Following are the topics discussed:

#python #python strings #strings in python