How to Print a Text File Backwards in Python
Learn how to read a text file and print its contents in reverse order using Python. Simple step-by-step guide included!
---
This video is based on the question https://stackoverflow.com/q/65638888/ asked by the user 'NoemonGR' ( https://stackoverflow.com/u/10764842/ ) and on the answer https://stackoverflow.com/a/65638916/ provided by the user 'Vaebhav' ( https://stackoverflow.com/u/9108912/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.
Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Print txt file backwards, character by character
Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.
If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
How to Print a Text File Backwards in Python
Have you ever found yourself needing to print the contents of a text file in reverse order? If you’re working with Python, you might have encountered some challenges when trying to achieve this. In this post, we will explore how to read a .txt file and print its contents backwards, character by character.
Understanding the Problem
Let's say you have a text file containing the word QWE, and you want to print it in reverse order. You might think that slicing the string with Python's slice notation [::-1] would do the trick, but that approach doesn’t work directly when reading from a file.
Below, we will present a solution that enables you to achieve the desired output by reading through the file and printing the characters in reverse order.
Solution Overview
To print the contents of a text file backwards, we can follow these steps:
Open the text file for reading.
Read the contents of the file.
Reverse the contents.
Iterate over the reversed contents and print each character.
Step-by-Step Implementation
Step 1: Open and Read the File
You can open the text file and read its contents using the open() function. For example:
[[See Video to Reveal this Text or Code Snippet]]
Step 2: Reverse the Contents
To reverse the contents of the file, we will use slicing. The idea is to iterate through the lines of the file from end to start:
[[See Video to Reveal this Text or Code Snippet]]
Step 3: Print Characters with Calculated Output
As you loop through each character, you can also calculate additional values. In this case, we will calculate 128 - ord(char):
[[See Video to Reveal this Text or Code Snippet]]
Complete Code Example
Putting it all together, here is the complete code to reverse the character order of a text file:
[[See Video to Reveal this Text or Code Snippet]]
Expected Output
Using the code above with a file containing QWE, you will get the output as follows:
[[See Video to Reveal this Text or Code Snippet]]
This output displays the characters in reverse order, along with their respective ASCII values and calculations.
Conclusion
Reversing the content of a text file in Python is straightforward once you understand how to manipulate strings and file operations. By reading the file, reversing its contents, and printing character by character, you can customize the output to fit your needs.
With this simple method, you can tackle various tasks, from text manipulation to data processing with ease! Keep experimenting with different files and functions to enhance your programming skills.
