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How to Create a Symmetric Array in Python: A Fun Logic Exercise

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 Here's a Python program that says to write a Symmetric array transformation. A top interview question. Symmetric Array Transformation Problem: Write a Python function that transforms a given array into a symmetric array by mirroring it around its center. For example: Input: [1, 2, 3] Output: [1, 2, 3, 2, 1] Hints: Use slicing for the reverse part. Concatenate the original array with its mirrored part. Example def symmetric_array(arr):     """     Transforms the input array into a symmetric array by mirroring it around its center.     Parameters:     arr (list): The input array.     Returns:     list: The symmetric array.     """     # Mirror the array by concatenating the original with its reverse (excluding the last element to avoid duplication)     return arr + arr[-2::-1] # Example usage input_array = [1, 2, 3] symmetric_result = symmetric_array(input_array) print("Input Array:", input_arr...

Python Regex: The 5 Exclusive Examples

 Regular expressions (regex) are powerful tools for pattern matching and text manipulation in Python. Here are five Python regex examples with explanations:


Regular expression examples


01 Matching a Simple Pattern


import re


text = "Hello, World!"

pattern = r"Hello"

result = re.search(pattern, text)

if result:

    print("Pattern found:", result.group())

Output:


Output:

Pattern found: Hello

This example searches for the pattern "Hello" in the text and prints it when found.


02 Matching Multiple Patterns


import re


text = "The quick brown fox jumps over the lazy dog."

patterns = [r"fox", r"dog"]

for pattern in patterns:

    if re.search(pattern, text):

        print(f"Pattern '{pattern}' found.")

Output:


Pattern 'fox' found.

Pattern 'dog' found.

It searches for both "fox" and "dog" patterns in the text and prints when they are found.


03 Matching Any Digit

 

import re


text = "The price of the product is $99.99."

pattern = r"\d+"

result = re.search(pattern, text)

if result:

    print("Price:", result.group())

Output:


Price: 99

This example extracts digits (numbers) from the text.


04 Matching Email Addresses


import re


text = "Contact us at support@example.com or info@example.org."

pattern = r"\b[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Z|a-z]{2,7}\b"

emails = re.findall(pattern, text)

for email in emails:

    print("Email:", email)

Output:

Email: support@example.com

Email: info@example.org

It extracts email addresses from the text using a common email pattern.


05. Replacing Text

 

import re

text = "Please visit our website at http://www.example.com."

pattern = r"http://www\.[A-Za-z]+\.[A-Za-z]+"

replacement = "https://www.example.com"

updated_text = re.sub(pattern, replacement, text)

print("Updated Text:", updated_text)

Output:

Updated Text: Please visit our website at https://www.example.com.

This example replaces a URL with a different URL in the text.


These are just a few examples of what you can do with regular expressions in Python. Regex is a versatile tool for text processing, and you can create complex patterns to match specific text structures or extract information from text data.

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