Practice set 0: first steps

Beginner questions that still come up as warm-ups in interviews. Try each one in your editor before reading the answer.

Q1Print the numbers 1 to 15, but "Fizz" for multiples of 3, "Buzz" for multiples of 5 and "FizzBuzz" for both.DADEEASY

Approach: Check the "both" case first, because 15 is also a multiple of 3. Use % for "is a multiple of".

out = []
for n in range(1, 16):
    if n % 15 == 0:
        out.append("FizzBuzz")
    elif n % 3 == 0:
        out.append("Fizz")
    elif n % 5 == 0:
        out.append("Buzz")
    else:
        out.append(str(n))
print(" ".join(out))

1 2 Fizz 4 Buzz Fizz 7 8 Fizz Buzz 11 Fizz 13 14 FizzBuzz

Q2Find the largest and smallest amount without using max() or min().DADEEASY

Approach: Track the best so far (Lesson 8). Start from the first item, not from 0, or negative numbers break it.

amounts = [1198, 796, 1499, 1999, 747, 3498]
low = high = amounts[0]
for a in amounts[1:]:
    if a > high:
        high = a
    if a < low:
        low = a
print(low, high)

747 3498

Q3Count how many times each word appears in a sentence, ignoring case.DADEEASY

Approach: Lowercase, split into words, then count with a dict (Lesson 12).

text = "Data pipelines move data and data pipelines fail"
counts = {}
for word in text.lower().split():
    counts[word] = counts.get(word, 0) + 1
print(counts)

{'data': 3, 'pipelines': 2, 'move': 1, 'and': 1, 'fail': 1}

Q4Check whether a string reads the same backwards, ignoring spaces and case.DADEEASY

Approach: Keep only letters, lowercase them, compare with the reversed slice [::-1].

def is_palindrome(text):
    letters = "".join(ch.lower() for ch in text if ch.isalpha())
    return letters == letters[::-1]

print(is_palindrome("Never odd or even"), is_palindrome("Python"))

True False

Q5Given a list of order statuses, return each status with the share of orders it makes up, as a percentage.DAEASY

Approach: Count first, then divide each count by the total. Format with f-strings (Lesson 4).

statuses = []
with open("orders.csv") as f:
    next(f)
    for line in f:
        statuses.append(line.strip().split(",")[3])
counts = {}
for s in statuses:
    counts[s] = counts.get(s, 0) + 1
for s, n in counts.items():
    print(f"{s:<10} {n:>2}  {n / len(statuses):.1%}")

delivered  12  80.0%
cancelled   2  13.3%
returned    1  6.7%