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In Python, a list comprehension is a concise and elegant way to create lists. It allows you to generate a new list by applying an expression to each item in an existing iterable (like a list or range), often in a single line of code, making it more readable and compact than a traditional for loop.

# Traditional way using a for loop
squares_loop = []
for i in range(10):
    squares_loop.append(i i)

print(f"Using a loop: {squares_loop}")

The Pythonic way using a list comprehension

squares_comp = [i i for i in range(10)]

print(f"Using comprehension: {squares_comp}")

You can also add conditions

even_squares = [i * i for i in range(10) if i % 2 == 0]
print(f"Even squares only: {even_squares}")

Both the loop and the basic list comprehension produce the exact same result: a list of the first 10 square numbers. However, the list comprehension is more efficient and easier to read once you are familiar with the syntax.

#Python #ListComprehension #PythonTips #CodeExamples #Programming #Pythonic #Developer #Code

By: @DataScienceQ 🩵
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The Walrus Operator := (Assignment Expressions)

Introduced in Python 3.8, the "walrus operator" := allows you to assign a value to a variable as part of a larger expression. It's a powerful tool for writing more concise and readable code, especially in while loops and comprehensions.

It solves the common problem where you need to compute a value, check it, and then use it again.

---

#### The Old Way: Repetitive Code

Consider a loop that repeatedly prompts a user for input and stops when the user enters "quit".

# We have to get the input once before the loop,
# and then again inside the loop.
command = input("Enter command: ")

while command != "quit":
print(f"Executing: {command}")
command = input("Enter command: ")

print("Exiting program.")

Notice how input("Enter command: ") is written twice.

---

#### The Pythonic Way: Using the Walrus Operator :=

The walrus operator lets you capture the value and test it in a single, elegant line.

while (command := input("Enter command: ")) != "quit":
print(f"Executing: {command}")

print("Exiting program.")

Here, (command := input(...)) does two things:
• Calls input() and assigns its value to the command variable.
• The entire expression evaluates to that same value, which is then compared to "quit".

This eliminates redundant code, making your logic cleaner and more direct.

#Python #PythonTips #PythonTricks #WalrusOperator #Python3 #CleanCode #Programming #Developer #CodingTips

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By: @DataScienceQ
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