## Are you ready?

**10 questions** to solve

Instructions

- This quiz goes to full-screen once you press the Start button.
- At the end of the quiz, you are able to review all the questions that you answered wrong and see their explanations.

What does the following list comprehension produce?

`[0 for i in range(5)]`

In each iteration over the sequence

`range(5)`

, the value `0`

is pushed onto the list, ultimately giving `[0, 0, 0, 0, 0]`

. Hence the correct choice is (B). For more details, refer to Python List Comprehensions.What is the value of

`l`

in the code below?`l = [i * i for i in range(3)]`

For each iteration over the sequence

`range(3)`

(i.e *0, 1, 2*), the square of the current element is pushed onto the list, ultimately giving`[0, 1, 4]`

. This goes with choice (B). For more details, refer to Python List Comprehensions.What is the value of

`l`

in the code below?`l = [0 if x % 2 == 0 else x for x in range(10)]`

For each element in the sequence

`range(10)`

(i.e *0, 1, 2, 3, 4, 5, 6, 7, 8, 9*), if it's divisible by`2`

, `0`

is pushed onto the list, or else the element itself. This leads to the list `[0, 1, 0, 3, 0, 5, 0, 7, 0, 9]`

, which goes with choice (B). For more details, refer to Python List Comprehensions â€” conditional expressions.What does the following code print?

```
l1 = [0 for i in range(10)]
l2 = [0 if x % 2 == 0 else x for x in range(0, 20, 2)]
print(l1 == l2)
```

The first comprehension iterates over the sequence

Hence, these two lists are equal to one another, which goes with choice (A). For more details, refer to Python List Comprehensions â€” conditional expressions.

`range(10)`

and pushes `0`

in each iteration, thus giving a list of 10 `0`

s. The second comprehension iterates over the sequence `range(0, 20, 2)`

(the first 10 non-negative evens) and pushes `0`

if the current element is divisible by `2`

, or else `x`

. Since, all elements are divisible by `2`

, every element in the list is `0`

. This list also consists of 10 `0`

's.Hence, these two lists are equal to one another, which goes with choice (A). For more details, refer to Python List Comprehensions â€” conditional expressions.

What does the following code print?

```
s = 'Hello World!'
l = [_s.upper() for _s in s[:-1]]
print(l)
```

The comprehension iterates over

Hence, the correct choice is (A). For more details, refer to Python List Comprehensions â€” function calls.

`s[:-1]`

, which is the string `'Hello World'`

, and pushes each character's uppercased version onto the list. This yields `['H', 'E', 'L', 'L', 'O', ' ', 'W', 'O', 'R', 'L', 'D']`

.Hence, the correct choice is (A). For more details, refer to Python List Comprehensions â€” function calls.

What does the following code print?

```
words = ['Bye', 'OK', 'Savage', 'Love', 'Calibrate', 'Height', 'Linguistic']
print([word for word in words if len(word) <= 3])
```

The comprehension iterates over

`words`

and pushes only those elements whose length is lesser than or equal to `3`

. This gives the list `['Bye', 'OK']`

, which goes with choice (A). For more details, refer to Python List Comprehensions â€” the `if`

clause.What does the following code print?

```
nums = [0, -5, 3, -9, -6, -11, 0, 0, 5, 3, 27]
print([num for num in nums if num % 3 == 0][:-2])
```

The comprehension iterates over

Hence the correct choice is (B). For more details, refer to Python List Comprehensions â€” the

`nums`

and pushes all those elements that are divisible by `3`

. This gives the list `[0, 3, -9, -6, 0, 0, 3, 27]`

. Next, this list is sliced from the beginning to the third-last element, giving `[0, 3, -9, -6, 0, 0]`

.Hence the correct choice is (B). For more details, refer to Python List Comprehensions â€” the

`if`

clause.What is the value of

`l`

in the code below?`l = [i + j for i in range(2) for j in range(5)]`

Each element in the sequence

`range(2)`

(i.e *0, 1*) is added one-by-one to each element in the sequence`range(5)`

(i.e *0, 1, 2, 3, 4*). This gives`[0, 1, 2, 3, 4, 1, 2, 3, 4, 5]`

, which goes with choice (A). For more details, refer to Python List Comprehensions â€” nested loops.What is the value of

`l`

in the code below?`l = [i for i in [i for i in range(5)][:-4]]`

First, the inner comprehension

Hence, the correct choice is (A). For more details, refer to Python List Comprehensions.

`[i for i in range(5)]`

is evaluated. It's simply the list `[0, 1, 2, 3, 4]`

. Next, this list is sliced from the beginning to the first character which merely gives `[0]`

. The outer comprehension iterates over this list `[0]`

, and pushes each element onto the main list, once again, merely giving `[0]`

.Hence, the correct choice is (A). For more details, refer to Python List Comprehensions.

What is the value of

`l`

in the code below?`l = [[i for j in range(2)] for i in range(3)]`

For each element in the sequence

Hence, the correct choice is (B). For more details, refer to Python List Comprehensions â€” 2D lists.

`range(3)`

, the comprehension `[i for j in range(2)]`

is evaluated and pushed onto the main list. `[i for j in range(2)]`

simply iterates over `range(2)`

and pushes `i`

for each element, thus giving `[i, i]`

. So, for each iteration of the main comprehension, `[i, i]`

is pushed onto the main list. This gives `[[0, 0], [1, 1], [2, 2]]`

.Hence, the correct choice is (B). For more details, refer to Python List Comprehensions â€” 2D lists.