Скачать или смотреть How to Compare Last Digits of Two Files in Python and Print Results

Learn how to effectively compare the last digits of two files in Python, and output matching lines to a new file using simple coding techniques.
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Comparing Last Digits of Two Files in Python

When working with data in files, there might be times you need to compare entries across different files based on specific criteria. One common task is to compare the last digit of entries from two separate files and print matching lines. If you find yourself facing this situation, you're in the right place! In this guide, we're going to walk you through the process of achieving this in Python, step by step.

The Problem

You have two files: file1 and file2. The goal is to compare the last digit of every line in these two files. If the last digits match, you'll want to print the matched lines from file1 into a new file called fout.

Example Files

Here's a quick look at the contents of your files:

file1:

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file2:

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The expected output in fout should include:

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Proposed Solution

Let's break down the solution into clear and manageable steps.

Step 1: Read the Files into Lists

To efficiently work with the data, start by loading the contents of your files into lists. By doing so, you will easily loop through the lines without worrying about line breaks.

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Step 2: Loop Through Line Comparisons

Next, you will create a loop to compare the last character of each line from both lists. Here’s how you can achieve that:

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Step 3: Using List Comprehension

If you're looking for a more concise way to accomplish this, you can use Python's list comprehension. This will help you create a new list of all lines from file1 that share the same last digit with lines in file2.

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This will create a list called common, which contains all matching lines. The output will be:

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Step 4: Writing the Output to a New File

Finally, to write the matching lines into fout, you can simply loop through the common list and use the file write method:

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This will create (or overwrite) the fout file with the relevant information based on the last digit comparisons.

Conclusion

In summary, comparing the last digits of two files in Python is a straightforward process that you can manage by breaking it down into simple steps. By reading the files into lists, looping through the contents, and utilizing list comprehension, you can efficiently extract the desired information and write it to a new file. Happy coding!