Python Coding Challange - Question With Answer(01191224)

 

What does the following Python code do?

arr = [10, 20, 30, 40, 50]
result = arr[1:4]
print(result)

[10, 20, 30]
[20, 30, 40]
[20, 30, 40, 50]
[10, 20, 30, 40]

Step 1: Understand arr[1:4]

The slicing syntax arr[start:end] extracts a portion of the list from index start to end-1.

• start (1): This is the index where slicing begins (inclusive).
• end (4): This is the index where slicing ends (exclusive).

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Step 2: Index Positions in the Array

The array arr is:

Index:   0   1   2   3   4
Values: [10, 20, 30, 40, 50]

• start = 1: The slicing starts at index 1, which is 20.
• end = 4: The slicing stops before index 4, so it includes elements up to index 3 (40).

The sliced portion is:

[20, 30, 40]

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Step 3: Assigning to result

The sliced subarray [20, 30, 40] is stored in result.

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Step 4: Printing the Result

When you print result, the output is:

[20, 30, 40]

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Key Takeaways:

1. Slicing includes the start index but excludes the end index.
   So arr[1:4] includes indices 1, 2, and 3 but not 4.
2. The result is [20, 30, 40], the portion of the array between indices 1 and 3.