Python: Built-In Functions and Upto Tuple

What will print([1, 2, 3] + [4, 5]) output?

• [1, 2, 3, 4, 5]

• [5, 4, 3, 2, 1]

• Error

• [1, 2, 3, [4, 5]]

Answer explanation

The + operator concatenates two lists.

Which of the following will create a shallow copy of a list a?

• 
  b = a[:]

• 
  b = a.copy()

• 
  b = a[:]
  and
  b = a.copy()
  both options correct

• 
  None of the above

Answer explanation

Both slicing and copy() create a shallow copy of the list.

What will print(len([[1, 2], [3, 4]])) return?

• 2

• 4

• 8

• Error

Answer explanation

The len() function returns the number of top-level elements, which is 2.

Which of the following will raise an error for tuple a?

• 
  a = (1, 2)

• 
  a[0] = 3

• 
  len((1, 2, 3))

• 
  (1, 2) + (3,)

Answer explanation

Tuples are immutable; modifying an element is not allowed.

What is the output of print((1, 2) * 2)?

• 
  (1, 2, 1, 2)

• 
  (1, 2, 2)

• 
  Error

• 
  

  [1, 2, 1, 2]

Answer explanation

The * operator repeats the tuple.

What will the following code output?
for i in range(3):
 ↳ for j in range(2):
 ↳ print(i * j, end=" ")

Note:  ↳ indicating that the statement is the part of its above block

• 0 0 0 1 0 2

• 
  0 0 0 0 0 1

• 
  0 0 0 1

• 
  0 0 0 0 1 2

Answer explanation

The nested loops compute i * j for all combinations of i and j.

Error Correction: Fix the code to break the loop:
i = 0

while True:

↳print(i)

↳if i == 5:

↳break

Note:  ↳ indicating that the statement is the part of its above block

• Add i += 1 before break

• Use for instead of while

• Add i += 1 after print(i)

• 
  Replace break with continue

Answer explanation

Increment i after print(i) to avoid an infinite loop.

What will be the output of the following code?
s = "hello"
print(s[-1:-5:-1])

• 
  olleh

• hello

• 
  olle

• 
  Error

Answer explanation

Start from -1 index and stop at -4 (Stop always exclusive), and -1 stepping means from last to first (reverse).

What is the result of
''.join(sorted("cabac"))?

• 
  cabac

• 
  aabcc

• 
  abacc

• 
  Error

Answer explanation

The sorted() function returns a sorted list of characters (['a', 'a', 'b', 'c', 'c']), which is then joined into the string aabcc

Which of the following results in a valid deep copy of a list?

• 
  b = a.copy()

• b = copy.deepcopy(a)

• b = a[:]

• b = list(a)

Answer explanation

Only copy.deepcopy() creates a deep copy of nested lists, while the others create shallow copies.

In Python, when copying a list, copy.deepcopy(a) creates a "deep copy," meaning it generates a completely independent copy where changes to the copied list won't affect the original, while copy.copy(a) creates a "shallow copy," which only copies the top-level elements, so modifying nested lists in the copy will also modify the original list.

Deep Copy can be slower than a shallow copy due to the recursive operation.