Python Coding Questions and Answers

Python Coding Questions and Answers

Reverse a String

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

print(reverse_string("Python"))

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Check Even or Odd

num = 7
print("Even" if num % 2 == 0 else "Odd")

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Swap Two Numbers

a, b = 5, 10
a, b = b, a
print(a, b)

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Find Largest in List

numbers = [10, 25, 5, 40]
print(max(numbers))

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Check Palindrome

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

print(is_palindrome("madam"))

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Count Vowels

def count_vowels(s):
    return sum(1 for char in s if char.lower() in "aeiou")

print(count_vowels("Hello World"))

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Factorial of Number

def factorial(n):
    return 1 if n == 0 else n * factorial(n-1)

print(factorial(5))

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Fibonacci Series

a, b = 0, 1
for _ in range(10):
    print(a, end=" ")
    a, b = b, a + b

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Check Prime Number

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

print(is_prime(11))

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Sum of List Elements

numbers = [1, 2, 3, 4]
print(sum(numbers))

Remove Duplicates from List
numbers = [1, 2, 2, 3, 4]
print(list(set(numbers)))

Find Second Largest Number
nums = [10, 20, 4, 45, 99]
nums = list(set(nums))
nums.sort()
print(nums[-2])

Sort Dictionary by Value
data = {"a": 3, "b": 1, "c": 2}
print(dict(sorted(data.items(), key=lambda x: x[1])))

Count Character Frequency
from collections import Counter

print(Counter("hello"))

Merge Two Lists
list1 = [1, 3, 5]
list2 = [2, 4, 6]
print(sorted(list1 + list2))

Check Anagram
def is_anagram(a, b):
    return sorted(a) == sorted(b)

print(is_anagram("listen", "silent"))

Find Missing Number (1 to n)
def find_missing(nums, n):
    return n*(n+1)//2 - sum(nums)

print(find_missing([1,2,4,5], 5))

Flatten a List
nested = [[1,2], [3,4], [5]]
flat = [item for sublist in nested for item in sublist]
print(flat)


Check Armstrong Number
num = 153
order = len(str(num))
sum_val = sum(int(digit)**order for digit in str(num))
print(sum_val == num)

Find GCD of Two Numbers
import math
print(math.gcd(12, 18))

Find Duplicate in List
nums = [1,2,3,4,2]
seen = set()
for n in nums:
    if n in seen:
        print("Duplicate:", n)
        break
    seen.add(n)

Check Balanced Parentheses
def is_balanced(s):
    stack = []
    for char in s:
        if char == "(":
            stack.append(char)
        elif char == ")":
            if not stack:
                return False
            stack.pop()
    return not stack

print(is_balanced("(())"))

Find Longest Word in Sentence
sentence = "Python programming is powerful"
print(max(sentence.split(), key=len))

Reverse Words in Sentence
s = "Hello Python World"
print(" ".join(s.split()[::-1]))

Find Intersection of Two Lists
a = [1,2,3]
b = [2,3,4]
print(list(set(a) & set(b)))

Generate Random Password
import random
import string

password = ''.join(random.choices(string.ascii_letters + string.digits, k=8))
print(password)

Find First Non-Repeating Character
from collections import Counter

s = "aabbcde"
count = Counter(s)

for char in s:
    if count[char] == 1:
        print(char)
        break

Binary Search
def binary_search(arr, target):
    low, high = 0, len(arr)-1
    while low <= high:
        mid = (low+high)//2
        if arr[mid] == target:
            return mid
        elif arr[mid] < target:
            low = mid+1
        else:
            high = mid-1
    return -1

print(binary_search([1,2,3,4,5], 4))

Decorator Example
def decorator(func):
    def wrapper():
        print("Before function call")
        func()
        print("After function call")
    return wrapper

@decorator
def greet():
    print("Hello!")

greet()


Lambda with Map
nums = [1,2,3,4]
squared = list(map(lambda x: x**2, nums))
print(squared)