What Python coding interview questions and answers to prepare?

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Preparing for a Python coding interview involves familiarizing yourself with a range of questions that test your understanding of Python concepts, data structures, algorithms, and problem-solving skills. Here are some common Python coding interview questions along with their explanations and answers to help you prepare:

1. Reverse a String

Question: Write a function to reverse a string.

Answer:

def reverse_string(s):
    return s[::-1]

# Example usage
print(reverse_string("hello"))  # Output: "olleh"

2. Check for Palindrome

Question: Write a function that checks if a string is a palindrome.

Answer:

def is_palindrome(s):
    return s == s[::-1]

# Example usage
print(is_palindrome("racecar"))  # Output: True
print(is_palindrome("hello"))     # Output: False

3. Find the Largest Element in a List

Question: Write a function that finds the largest element in a list.

Answer:

def find_largest(numbers):
    return max(numbers)

# Example usage
print(find_largest([1, 2, 3, 4, 5]))  # Output: 5

4. Fibonacci Sequence

Question: Write a function to generate the Fibonacci sequence up to n terms.

Answer:

def fibonacci(n):
    sequence = [0, 1]
    while len(sequence) < n:
        sequence.append(sequence[-1] + sequence[-2])
    return sequence[:n]

# Example usage
print(fibonacci(10))  # Output: [0, 1, 1, 2, 3, 5, 8, 13, 21, 34]

5. Sum of All Elements in a List

Question: Write a function to calculate the sum of all elements in a list.

Answer:

def sum_list(numbers):
    return sum(numbers)

# Example usage
print(sum_list([1, 2, 3, 4, 5]))  # Output: 15

6. Find Duplicates in a List

Question: Write a function to find duplicates in a list.

Answer:

def find_duplicates(nums):
    seen = set()
    duplicates = set()
    for num in nums:
        if num in seen:
            duplicates.add(num)
        seen.add(num)
    return list(duplicates)

# Example usage
print(find_duplicates([1, 2, 3, 2, 4, 5, 3]))  # Output: [2, 3]

7. Sort a List

Question: Write a function to sort a list.

Answer:

def sort_list(lst):
    return sorted(lst)

# Example usage
print(sort_list([5, 3, 6, 2, 8]))  # Output: [2, 3, 5, 6, 8]

8. Count Vowels in a String

Question: Write a function to count the number of vowels in a string.

Answer:

def count_vowels(s):
    vowels = "aeiouAEIOU"
    return sum(1 for char in s if char in vowels)

# Example usage
print(count_vowels("hello world"))  # Output: 3

9. Merge Two Sorted Lists

Question: Write a function to merge two sorted lists into one sorted list.

Answer:

def merge_sorted_lists(list1, list2):
    return sorted(list1 + list2)

# Example usage
print(merge_sorted_lists([1, 3, 5], [2, 4, 6]))  # Output: [1, 2, 3, 4, 5, 6]

10. Check if a Number is Prime

Question: Write a function to check if a number is prime.

Answer:

def is_prime(n):
    if n <= 1:
        return False
    for i in range(2, int(n**0.5) + 1):
        if n % i == 0:
            return False
    return True

# Example usage
print(is_prime(11))  # Output: True
print(is_prime(4))   # Output: False