POC Data Structures & File Handling 3

Question 1

What is the output of `sorted({'b': 2, 'a': 1, 'c': 3})`?

Accepted Answer

['a', 'b', 'c']

Answer

`sorted()` on a dictionary iterates over its keys and returns them in sorted order as a list.

Question 2

Which data structure should you use to count the frequency of each word in a text efficiently?

Accepted Answer

collections.Counter

Answer

`collections.Counter` is a dict subclass designed to count hashable objects, making it ideal for frequency analysis.

Question 3

What exception is raised when you try to read from a file opened in write-only mode (`'w'`)?

Accepted Answer

UnsupportedOperation

Answer

`io.UnsupportedOperation` (a subclass of `OSError`) is raised when an unsupported operation like reading is attempted on a write-only file.

Question 4

What does `list.extend([4, 5])` do compared to `list.append([4, 5])`?

Accepted Answer

extend adds each element individually; append adds the list as a single element

Answer

`extend()` unpacks the iterable and adds each item, while `append()` inserts the whole object as a single new element.

Question 5

What is the output of `tuple([1, 2, 3]) == (1, 2, 3)`?

Accepted Answer

True

Answer

`tuple([1, 2, 3])` constructs the tuple `(1, 2, 3)`, which compares equal to the literal `(1, 2, 3)`.

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