Скачать или смотреть How to Copy-Paste Blocks of Text between Files Using Python

Learn how to efficiently `replace coordinates` in a file using Python, by copying data from one file to another in a structured way.
---
This video is based on the question https://stackoverflow.com/q/65640478/ asked by the user 'megamence' ( https://stackoverflow.com/u/14024882/ ) and on the answer https://stackoverflow.com/a/65640671/ provided by the user 'Matt Miguel' ( https://stackoverflow.com/u/14941819/ ) 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: How to "copy-paste" blocks of text from one file to another using python?

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 Copy-Paste Blocks of Text between Files Using Python

When you're managing data files in tasks like molecular simulations, you may often find yourself needing to transfer specific pieces of text from one file to another. For example, if you have a file containing molecular coordinates (typically in a .xyz format) and you need to replace certain coordinates in an input file for your simulations, Python can do the heavy lifting for you.

In this guide, we will walk you through the process of copying data from one file and pasting it into specific positions in another file, all using Python. This method is especially useful for scenarios where you have fixed formats like input files for molecular simulations.

The Problem

Imagine you have an input file (inputfile.py) that looks like this:

[[See Video to Reveal this Text or Code Snippet]]

And you have generated a set of coordinates which are stored in another file (conformer_coords.xyz):

[[See Video to Reveal this Text or Code Snippet]]

Your objective is to replace the coordinates in inputfile.py with the new coordinates from conformer_coords.xyz, keeping the structure of the input file intact. The coordinates you want to insert are located between the lines { and }.

The Solution

Step 1: Import Required Modules

Python's re module (regular expressions) will help us manage the text processing. Make sure to start with this import:

[[See Video to Reveal this Text or Code Snippet]]

Step 2: Define the Function

We will create a function to handle the entire process of reading files, extracting data, and writing to a new output file. Here's how you can define this function:

[[See Video to Reveal this Text or Code Snippet]]

Step 3: Read and Extract Data

Inside the function, first read the coordinates from the conformer_coords.xyz file. Use regular expressions to locate and capture the relevant data conveniently:

[[See Video to Reveal this Text or Code Snippet]]

Step 4: Capture Relevant Sections from the Input File

Next, you need to capture the portions of inputfile.py that come before and after the coordinate section. Utilize regular expressions to handle this efficiently.

[[See Video to Reveal this Text or Code Snippet]]

Step 5: Write to the Output File

Finally, bring it all together and write the pre-existing content combined with the new coordinates into an output file:

[[See Video to Reveal this Text or Code Snippet]]

Full Function Example

Here’s the complete function to do all of the above:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

By following the steps outlined above, you can easily copy-paste blocks of text from one file to another using Python. This method is not only practical for your molecular simulations but can also be adapted for various data-processing tasks involving structured text files.

Feel free to expand the function and enhance its capabilities as needed. Happy coding!