# Python Programming Puzzles - Exercises, Practice, Solution

## Python Programming Puzzles [100 exercises with solution]

[*An editor is available at the bottom of the page to write and execute the scripts.*]

**1.** Write a Python program find a list of integers with exactly two occurrences of nineteen and at least three occurrences of five. Go to the editor

Input:

[19, 19, 15, 5, 3, 5, 5, 2]

Output:

True

Input:

[19, 15, 15, 5, 3, 3, 5, 2]

Output:

False

Input:

[19, 19, 5, 5, 5, 5, 5]

Output:

True

Click me to see the sample solution

**2.** Write a Python program that accept a list of integers and check the length and the fifth element. Return true if the length of the list is 8 and fifth element occurs thrice in the said list. Go to the editor

Input:

[19, 19, 15, 5, 5, 5, 1, 2]

Output:

True

Input:

[19, 15, 5, 7, 5, 5, 2]

Output:

False

Input:

[11, 12, 14, 13, 14, 13, 15, 14]

Output:

True

Input:

[19, 15, 11, 7, 5, 6, 2]

Output:

False

Click me to see the sample solution

**3.** Write a Python program that accept an integer test whether an integer greater than 4^4 and which is 4 mod 34.

Input:

922

Output:

True

Input:

914

Output:

False

Input:

854

Output:

True

Input:

854

Output:

True

Click me to see the sample solution

**4.** We are making n stone piles! The first pile has n stones. If n is even, then all piles have an even number of stones. If n is odd, all piles have an odd number of stones. Each pile must more stones than the previous pile but as few as possible. Write a Python program to find the number of stones in each pile. Go to the editor

Input: 2

Output:

[2, 4]

Input: 10

Output:

[10, 12, 14, 16, 18, 20, 22, 24, 26, 28]

Input: 3

Output:

[3, 5, 7]

Input: 17

Output:

[17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49]

Click me to see the sample solution

**5.** Write a Python program to check the n^{th-1} string is a proper substring of n^{th} string in a given list of strings. Go to the editor

Input:

['a', 'abb', 'sfs', 'oo', 'de', 'sfde']

Output:

True

Input:

['a', 'abb', 'sfs', 'oo', 'ee', 'sfde']

Output:

False

Input:

['a', 'abb', 'sad', 'ooaaesdfe', 'sfsdfde', 'sfsd', 'sfsdf', 'qwrew']

Output:

False

Input:

['a', 'abb', 'sad', 'ooaaesdfe', 'sfsdfde', 'sfsd', 'sfsdf', 'qwsfsdfrew']

Output:

True

Click me to see the sample solution

**6.** Write a Python program to test a list of one hundred integers between 0 and 999, which all differ by ten from one another. Return true or false. Go to the editor

Input:

[0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500, 510, 520, 530, 540, 550, 560, 570, 580, 590, 600, 610, 620, 630, 640, 650, 660, 670, 680, 690, 700, 710, 720, 730, 740, 750, 760, 770, 780, 790, 800, 810, 820, 830, 840, 850, 860, 870, 880, 890, 900, 910, 920, 930, 940, 950, 960, 970, 980, 990]

Output:

True

Input:

[0, 20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280, 300, 320, 340, 360, 380, 400, 420, 440, 460, 480, 500, 520, 540, 560, 580, 600, 620, 640, 660, 680, 700, 720, 740, 760, 780, 800, 820, 840, 860, 880, 900, 920, 940, 960, 980]

Output:

False

Click me to see the sample solution

**7.** Write a Python program to check a given list of integers where the sum of the first i integers is i. Go to the editor

Input:

[0, 1, 2, 3, 4, 5]

Output:

False

Input:

[1, 1, 1, 1, 1, 1]

Output:

True

Input:

[2, 2, 2, 2, 2]

Output:

False

Click me to see the sample solution

**8.** Write a Python program to split a string of words separated by commas and spaces into two lists, words and separators. Go to the editor

Input: W3resource Python, Exercises.

Output:

[['W3resource', 'Python', 'Exercises.'], [' ', ', ']]

Input: The dance, held in the school gym, ended at midnight.

Output:

[['The', 'dance', 'held', 'in', 'the', 'school', 'gym', 'ended', 'at', 'midnight.'], [' ', ', ', ' ', ' ', ' ', ' ', ', ', ' ', ' ']]

Input: The colors in my studyroom are blue, green, and yellow.

Output:

[['The', 'colors', 'in', 'my', 'studyroom', 'are', 'blue', 'green', 'and', 'yellow.'], [' ', ' ', ' ', ' ', ' ', ' ', ', ', ', ', ' ']]

Click me to see the sample solution

**9.** Write a Python program to find list integers containing exactly four distinct values, such that no integer repeats twice consecutively among the first twenty entries. Go to the editor

Input:

[1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4]

Output:

True

Input:

[1, 2, 3, 3, 1, 2, 3, 3, 1, 2, 3, 3, 1, 2, 3, 3]

Output:

False

Input:

[1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3]

Output:

False

Click me to see the sample solution

**10.** Given a string consisting of whitespace and groups of matched parentheses, write a Python program to split it into groups of perfectly matched parentheses without any whitespace. Go to the editor

Input:

( ()) ((()()())) (()) ()

Output:

['(())', '((()()()))', '(())', '()']

Input:

() (( ( )() ( )) ) ( ())

Output:

['()', '((()()()))', '(())']

Click me to see the sample solution

**11.** Write a Python program to find the indexes of numbers of a given list below a given threshold. Go to the editor

Input:

[(100,(0, 12, 45, 3, 4923, 322, 105, 29, 15, 39, 55))]

Output:

[0, 1, 2, 3, 7, 8, 9, 10]

Input:

[(10,(0, 12, 4, 3, 49, 9, 1, 5, 3))]

Output:

[0, 2, 3, 5, 6, 7, 8]

Click me to see the sample solution

**12.** Write a Python program to check whether the given strings are palindromes or not. Return True, False. Go to the editor

Input:

['palindrome', 'madamimadam', '', 'foo', 'eyes']

Output:

[False, True, True, False, False]

Click me to see the sample solution

**13.** Write a Python program to find the strings in a given list, starting with a given prefix. Go to the editor

Input:

[( ca,('cat', 'car', 'fear', 'center'))]

Output:

['cat', 'car']

Input:

[(do,('cat', 'dog', 'shatter', 'donut', 'at', 'todo'))]

Output:

['dog', 'donut']

Click me to see the sample solution

**14.** Write a Python program to find the lengths of a given list of non-empty strings. Go to the editor

Input:

['cat', 'car', 'fear', 'center']

Output:

[3, 3, 4, 6]

Input:

['cat', 'dog', 'shatter', 'donut', 'at', 'todo', '']

Output:

[3, 3, 7, 5, 2, 4, 0]

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**15.** Write a Python program find the longest string of a given list of strings. Go to the editor

Input:

['cat', 'car', 'fear', 'center']

Output:

center

Input:

['cat', 'dog', 'shatter', 'donut', 'at', 'todo', '']

Output:

shatter

Click me to see the sample solution

**16.** Write a Python program find the strings in a given list containing a given substring. Go to the editor

Input:

[(ca,('cat', 'car', 'fear', 'center'))]

Output:

['cat', 'car']

Input:

[(o,('cat', 'dog', 'shatter', 'donut', 'at', 'todo', ''))]

Output:

['dog', 'donut', 'todo']

Input:

[(oe,('cat', 'dog', 'shatter', 'donut', 'at', 'todo', ''))]

Output:

[]

Click me to see the sample solution

**17.** Write a Python program to create string consisting of the non-negative integers up to n inclusive. Go to the editor

Input:

4

Output:

0 1 2 3 4

Input:

15

Output:

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

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**18.** An irregular/uneven matrix, or ragged matrix, is a matrix that has a different number of elements in each row. Ragged matrices are not used in linear algebra, since standard matrix transformations cannot be performed on them, but they are useful as arrays in computing.

Write a Python program to find the indices of all occurrences of target in the uneven matrix. Go to the editor

Input:

[([1, 3, 2, 32, 19], [19, 2, 48, 19], [], [9, 35, 4], [3, 19]),19]

Output:

[[0, 4], [1, 0], [1, 3], [4, 1]]

Input:

[([1, 2, 3, 2], [], [7, 9, 2, 1, 4]),2]

Output:

[[0, 1], [0, 3], [2, 2]]

Click me to see the sample solution

**19.** Write a Python program to split a given string (s) into strings if there is a space in the string, otherwise split on commas if there is a comma, otherwise return the list of lowercase letters with odd order (order of a = 0, b = 1, etc.) Go to the editor

Input:

a b c d

Split the said string into strings if there is a space in the string,

otherwise split on commas if there is a comma,

Output:

['a', 'b', 'c', 'd']

Input:

a,b,c,d

Split the said string into strings if there is a space in the string,

otherwise split on commas if there is a comma,

Output:

['a', 'b', 'c', 'd']

Input:

abcd

Split the said string into strings if there is a space in the string,

otherwise split on commas if there is a comma,

Output:

['b', 'd']

Click me to see the sample solution

**20.** Write a Python program to determine the direction ('increasing' or 'decreasing') of monotonic sequence numbers. Go to the editor

Input:

[1, 2, 3, 4, 5, 6]

Output:

Increasing.

Input:

[6, 5, 4, 3, 2, 1]

Output:

Decreasing.

Input:

[19, 19, 5, 5, 5, 5, 5]

Output:

Not a monotonic sequence!

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**21.** Write a Python program to check, for each string in a given list, whether the last character is an isolated letter or not. Return True or False. Go to the editor

Input:

['cat', 'car', 'fear', 'center']

Output:

[False, False, False, False]

Input:

['ca t', 'car', 'fea r', 'cente r']

Output:

[True, False, True, True]

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**22.** Write a Python program to compute the sum of the ASCII values of the upper-case characters in a given string. Go to the editor

Input:

PytHon ExerciSEs

Output:

373

Input:

JavaScript

Output:

157

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**23.** Write a Python program to find the indices for which the numbers in the list drops. Go to the editor

NOTE: You can detect multiple drops just by checking if nums[i] < nums[i-1]

Input:

[0, -1, 3, 8, 5, 9, 8, 14, 2, 4, 3, -10, 10, 17, 41, 22, -4, -4, -15, 0]

Output:

[1, 4, 6, 8, 10, 11, 15, 16, 18]

Input:

[6, 5, 4, 3, 2, 1]

Output:

[1, 2, 3, 4, 5]

Input:

[1, 19, 5, 15, 5, 25, 5]

Output:

[0, 2, 4, 6]

Click me to see the sample solution

**24.** Write a Python program to create a list whose i^{th} element is the maximum of the first i elements from a input list. Go to the editor

Input:

[0, -1, 3, 8, 5, 9, 8, 14, 2, 4, 3, -10, 10, 17, 41, 22, -4, -4, -15, 0]

Output:

[0, 0, 3, 8, 8, 9, 9, 14, 14, 14, 14, 14, 14, 17, 41, 41, 41, 41, 41, 41]

Input:

[6, 5, 4, 3, 2, 1]

Output:

[6, 6, 6, 6, 6, 6]

Input:

[1, 19, 5, 15, 5, 25, 5]

Output:

[1, 19, 19, 19, 19, 25, 25]

Click me to see the sample solution

**25.** Write a Python program to find the XOR of two given strings interpreted as binary numbers. Go to the editor

Input:

['0001', '1011']

Output:

0b1010

Input:

['100011101100001', '100101100101110']

Output:

0b110001001111

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**26.** Write a Python program to find the largest number where commas or periods are decimal points. Go to the editor

Input:

['100', '102,1', '101.1']

Output:

102.1

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**27.** Write a Python program to find x that minimizes mean squared deviation from a given a list of numbers. Go to the editor

Input:

[4, -5, 17, -9, 14, 108, -9]

Output:

17.142857142857142

Input:

[12, -2, 14, 3, -15, 10, -45, 3, 30]

Output:

1.1111111111111112

Click me to see the sample solution

**28.** Write a Python program to select a string from a given list of strings with the most unique characters. Go to the editor

Input:

['cat', 'catatatatctsa', 'abcdefhijklmnop', '124259239185125', '', 'foo', 'unique']

Output:

abcdefhijklmnop

Input:

['Green', 'Red', 'Orange', 'Yellow', '', 'White']

Output:

Orange

Click me to see the sample solution

**29.** Write a Python program to find the indices of two numbers that sum to 0 in a given list of numbers. Go to the editor

Input:

[1, -4, 6, 7, 4]

Output:

[4, 1]

Input:

[1232, -20352, 12547, 12440, 741, 341, 525, 20352, 91, 20]

Output:

[1, 7]

Click me to see the sample solution

**30.** Write a Python program to find the list of strings that has fewer total characters (including repetitions). Go to the editor

Input:

[['this', 'list', 'is', 'narrow'], ['I', 'am', 'shorter but wider']]

Output:

['this', 'list', 'is', 'narrow']

Input:

[['Red', 'Black', 'Pink'], ['Green', 'Red', 'White']]

Output:

['Red', 'Black', 'Pink']

Click me to see the sample solution

**31.** Write a Python program to find the coordinates of a triangle with the given side lengths. Go to the editor

Input:

[3, 4, 5]

Output:

[[0.0, 0.0], [3, 0.0], [3.0, 4.0]]

Input:

[5, 6, 7]

Output:

[[0.0, 0.0], [5, 0.0], [3.8, 5.878775382679628]]

Click me to see the sample solution

**32.** Write a Python program to rescale and shift numbers of a given list, so that they cover the range [0, 1]. Go to the editor

Input:

[18.5, 17.0, 18.0, 19.0, 18.0]

Output:

[0.75, 0.0, 0.5, 1.0, 0.5]

Input:

[13.0, 17.0, 17.0, 15.5, 2.94]

Output:

[0.7155049786628734, 1.0, 1.0, 0.8933143669985776, 0.0]

Click me to see the sample solution

**33.** Write a Python program to find the positions of all uppercase vowels (not counting Y) in even indices of a given string. Go to the editor

Input: w3rEsOUrcE

Output:

[6]

Input: AEIOUYW

Output:

[0, 2, 4]

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**34.** Write a Python program to find the sum of the numbers of a given list among the first k with more than 2 digits. Go to the editor

Input: [4, 5, 17, 9, 14, 108, -9, 12, 76]

Value of K: 4

Output:

0

Input: [4, 5, 17, 9, 14, 108, -9, 12, 76]

Value of K: 6

Output:

108

Input: [114, 215, -117, 119, 14, 108, -9, 12, 76]

Value of K: 5

Output:

331

Input: [114, 215, -117, 119, 14, 108, -9, 12, 76]

Value of K: 1

Output:

114

Click me to see the sample solution

**35.** Write a Python program to compute the product of the odd digits in a given number, or 0 if there aren't any. Go to the editor

Input: 123456789

Output:

945

Input: 2468

Output:

0

Input: 13579

Output:

945

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**36.** Write a Python program to find the largest k numbers from a given list of numbers. Go to the editor

Input: [1, 2, 3, 4, 5, 5, 3, 6, 2]

Output:

[6]

Input: [1, 2, 3, 4, 5, 5, 3, 6, 2]

Output:

[6, 5]

Input: [1, 2, 3, 4, 5, 5, 3, 6, 2]

Output:

[6, 5, 5]

Input: [1, 2, 3, 4, 5, 5, 3, 6, 2]

Output:

[6, 5, 5, 4]

Input: [1, 2, 3, 4, 5, 5, 3, 6, 2]

Output:

[6, 5, 5, 4, 3]

Click me to see the sample solution

**37.** Write a Python program to find the largest integer divisor of a number n that is less than n. Go to the editor

Input: 18

Output:

9

Input: 100

Output:

50

Input: 102

Output:

51

Input: 500

Output:

250

Input: 1000

Output:

500

Input: 6500

Output:

3250

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**38.** Write a Python program to sort the numbers of a given list by the sum of their digits. Go to the editor

Input: [10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20]

Output:

[10, 11, 20, 12, 13, 14, 15, 16, 17, 18, 19]

Input: [23, 2, 9, 34, 8, 9, 10, 74]

Output:

[10, 2, 23, 34, 8, 9, 9, 74]

Click me to see the sample solution

**39.** Write a Python program to determine which triples sum to zero from a given list of lists. Go to the editor

Input: [[1343532, -2920635, 332], [-27, 18, 9], [4, 0, -4], [2, 2, 2], [-20, 16, 4]]

Output:

[False, True, True, False, True]

Input: [[1, 2, -3], [-4, 0, 4], [0, 1, -5], [1, 1, 1], [-2, 4, -1]]

Output:

[True, True, False, False, False]

Click me to see the sample solution

**40.** Write a Python program to find string s that, when case is flipped gives target where vowels are replaced by chars two later. Go to the editor

Input: Python

Output:

pYTHQN

Input: aeiou

Output:

CGKQW

Input: Hello, world!

Output:

hGLLQ, WQRLD!

Input: AEIOU

Output:

cgkqw

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**41.** Write a Python program to sort numbers based on strings. Go to the editor

Input: six one four one two three

Output:

one two three four six

Input: six one four three two nine eight

Output:

one two three four six eight nine

Input: nine eight seven six five four three two one

Output:

one two three four five six seven eight nine

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**42.** Write a Python program to find the set of distinct characters in a given string, ignoring case. Go to the editor

Input: HELLO

Output:

['h', 'o', 'l', 'e']

Input: HelLo

Output:

['h', 'o', 'l', 'e']

Input: Ignoring case

Output:

['s', 'n', 'c', 'o', 'e', 'i', 'r', 'g', 'a', ' ']

Click me to see the sample solution

**43.** Write a Python program to find all words in a given string with n consonants. Go to the editor

Input: this is our time

Output:

Number of consonants: 3

Words in the said string with 3 consonants:

['this']

Number of consonants: 2

Words in the said string with 2 consonants:

['time']

Number of consonants: 1

Words in the said string with 1 consonants:

['is', 'our']

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**44.** Write a Python program to find which characters of a hexadecimal number correspond to prime numbers. Go to the editor

Input: 123ABCD

Output:

[False, True, True, False, True, False, True]

Input: 123456

Output:

[False, True, True, False, True, False]

Input: FACE

Output:

[False, False, False, False]

Click me to see the sample solution

**45.** Write a Python program to find all even palindromes up to n. Go to the editor

Output:

Even palindromes up to 50 -

[0, 3, 6, 9, 33]

Even palindromes up to 100 -

[0, 3, 6, 9, 33, 66, 99]

Even palindromes up to 500 -

[0, 3, 6, 9, 33, 66, 99, 111, 141, 171, 222, 252, 282, 303, 333, 363, 393, 414, 444, 474]

Even palindromes up to 2000 -

[0, 3, 6, 9, 33, 66, 99, 111, 141, 171, 222, 252, 282, 303, 333, 363, 393, 414, 444, 474, 525, 555, 585, 606, 636, 666, 696, 717, 747, 777, 828, 858, 888, 909, 939, 969, 999, 1221, 1551, 1881]

Click me to see the sample solution

**46.** Given an array of numbers representing a branch on a binary tree, write a Python program to find the minimum even value and its index. In the case of a tie, return the smallest index. If there are no even numbers, the answer is []. Go to the editor

Input:

[1, 9, 4, 6, 10, 11, 14, 8]

Output:

Minimum even value and its index of the said array of numbers:

[4, 2]

Input:

[1, 7, 4, 4, 9, 2]

Output:

Minimum even value and its index of the said array of numbers:

[2, 5]

Input:

[1, 7, 7, 5, 9]

Output:

Minimum even value and its index of the said array of numbers:

[]

Click me to see the sample solution

**47.** Write a Python program to Filter for the numbers in numbers in a given list whose sum of digits is > 0, where the first digit can be negative. Go to the editor

Input:

[11, -6, -103, -200]

Output:

[11, -103]

Input:

[1, 7, -4, 4, -9, 2]

Output:

[1, 7, 4, 2]

Input:

[10, -11, -71, -13, 14, -32]

Output:

[10, -13, 14]

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**48.** Write a Python program to find the indices of two entries that show that the list is not in increasing order. If there are no violations (they are increasing), return an empty list. Go to the editor

Input:

[1, 2, 3, 0, 4, 5, 6]

Output:

[2, 3]

Input:

[1, 2, 3, 4, 5, 6]

Output:

[]

Input:

[1, 2, 3, 4, 6, 5, 7]

Output:

[4, 5]

Input:

[-3, -2, -3, 0, 2, 3, 4]

Output:

[1, 2]

Click me to see the sample solution

**49.** Write a Python program to find the h-index, the largest positive number h such that h occurs in the sequence at least h times. If there is no such positive number return h = -1. Go to the editor

Input:

[1, 2, 2, 3, 3, 4, 4, 4, 4]

Output:

4

Input:

[1, 2, 2, 3, 4, 5, 6]

Output:

2

Input:

[3, 1, 4, 17, 5, 17, 2, 1, 41, 32, 2, 5, 5, 5, 5]

Output:

5

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**50.** Write a Python program to find the even-length words from a given list of words and sort them by length. Go to the editor

Input:

['Red', 'Black', 'White', 'Green', 'Pink', 'Orange']

Output:

['Pink', 'Orange']

Input:

['The', 'worm', 'ate', 'a', 'bird', 'imagine', 'that', '!', 'Absurd', '!!']

Output:

['!!', 'bird', 'that', 'worm', 'Absurd']

Click me to see the sample solution

**51.** Write a Python program to find the first n Fibonacci numbers. Go to the editor

Input: 10

Output:

[1, 1, 2, 3, 5, 8, 13, 21, 34, 55]

Input: 15

Output:

[1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610]

Input: 50

Output:

[1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2584, 4181, 6765, 10946, 17711, 28657, 46368, 75025, 121393, 196418, 317811, 514229, 832040, 1346269, 2178309, 3524578, 5702887, 9227465, 14930352, 24157817, 39088169, 63245986, 102334155, 165580141, 267914296, 433494437, 701408733, 1134903170, 1836311903, 2971215073, 4807526976, 7778742049, 12586269025]

Click me to see the sample solution

**52.** Write a Python program to reverse the case of all strings. For those strings, which contain no letters, reverse the strings. Go to the editor

Input:

['cat', 'catatatatctsa', 'abcdefhijklmnop', '124259239185125', '', 'foo', 'unique']

Output:

['CAT', 'CATATATATCTSA', 'ABCDEFHIJKLMNOP', '521581932952421', '', 'FOO', 'UNIQUE']

Input:

['Green', 'Red', 'Orange', 'Yellow', '', 'White']

Output:

['gREEN', 'rED', 'oRANGE', 'yELLOW', '', 'wHITE']

Input:

['Hello', '[email protected]#', '[email protected]#$', '123#@!']

Output:

['hELLO', '[email protected]#', '[email protected]#$', '123#@!']

Click me to see the sample solution

**53.** Write a Python program to find the product of the units digits in the numbers of a given list. Go to the editor

Input:

[12, 23]

Output:

6

Input:

[12, 23, 43]

Output:

18

Input:

[113, 234]

Output:

12

Input:

[1002, 2005]

Output:

10

Click me to see the sample solution

**54.** Write a Python program to remove duplicates from a list of integers, preserving order. Go to the editor

Input:

[1, 3, 4, 10, 4, 1, 43]

Output:

[1, 3, 4, 10, 43]

Input:

[10, 11, 13, 23, 11, 25, 23, 76, 99]

Output:

[10, 11, 13, 23, 25, 76, 99]

Click me to see the sample solution

**55.** Write a Python program to find the numbers that are greater than 10 and have odd first and last digits. Go to the editor

Input:

[1, 3, 79, 10, 4, 1, 39, 62]

Output:

[79, 39]

Input:

[11, 31, 77, 93, 48, 1, 57]

Output:

[11, 31, 77, 93, 57]

Click me to see the sample solution

**56.** Write a Python program to find an integer exponent x such that a^x = n. Go to the editor

Input:

a = 2 : n = 1024

Output:

10

Input:

a = 3 : n = 81

Output:

4

Input:

a = 3 : n = 1290070078170102666248196035845070394933441741644993085810116441344597492642263849

Output:

170

Click me to see the sample solution

**57.** Write a Python program to find the sum of the magnitudes of the elements in the array with a sign that is equal to the product of the signs of the entries. Go to the editor

Input:

[1, 3, -2]

Output:

-6

Input:

[1, -3, 3]

Output:

-7

Input:

[10, 32, 3]

Output:

45

Input:

[-25, -12, -23]

Output:

-60

Click me to see the sample solution

**58.** Write a Python program to find the biggest even number between two numbers inclusive. Go to the editor

Input:

m = 12

n = 51

Output:

50

Input:

m = 1

n = 79

Output:

78

Input:

m = 47

n = 53

Output:

52

Input:

m = 100

n = 200

Output:

200

Click me to see the sample solution

**59.** A valid filename should end in .txt, .exe, .jpg, .png, or .dll, and should have at most three digits, no additional periods. Write a Python program to create a list of True/False that determine whether candidate filename is valid or not. Go to the editor

Input:

['abc.txt', 'windows.dll', 'tiger.png', 'rose.jpg', 'test.py', 'win32.exe']

Output:

['Yes', 'Yes', 'Yes', 'Yes', 'No', 'Yes']

Input:

['.txt', 'windows.exe', 'tiger.jpeg', 'rose.c', 'test.java']

Output:

['No', 'Yes', 'No', 'No', 'No']

Click me to see the sample solution

**60.** Write a Python program to find a list of all numbers that are adjacent to a prime number in the list, sorted without duplicates. Go to the editor

Input:

[2, 17, 16, 0, 6, 4, 5]

Output:

[2, 4, 16, 17]

Input:

[1, 2, 19, 16, 6, 4, 10]

Output:

[1, 2, 16, 19]

Input:

[1, 2, 3, 5, 1, 16, 7, 11, 4]

Output:

[1, 2, 3, 4, 5, 7, 11, 16]

Click me to see the sample solution

**61.** Write a Python program to find the number which when appended to the list makes the total 0. Go to the editor

Input:

[1, 2, 3, 4, 5]

Output:

-15

Input:

[-1, -2, -3, -4, 5]

Output:

5

Input:

[10, 42, 17, 9, 1315182, 184, 102, 29, 15, 39, 755]

Output:

-1316384

Click me to see the sample solution

**62.** Write a Python program to find the dictionary key whose case is different than all other keys. Go to the editor

Input:

{'red': '', 'GREEN': '', 'blue': 'orange'}

Output:

GREEN

Input:

{'RED': '', 'GREEN': '', 'orange': '#125GD'}

Output:

orange

Click me to see the sample solution

**63.** Write a Python program to find the sum of the even elements that are at odd indices. Go to the editor

Input:

[1, 2, 3, 4, 5, 6, 7]

Output:

12

Input:

[1, 2, 8, 3, 9, 4]

Output:

6

Click me to see the sample solution

**64.** Write a Python program to find the string consisting of all the words whose lengths are prime numbers. Go to the editor

Input:

The quick brown fox jumps over the lazy dog.

Output:

The quick brown fox jumps the

Input:

Omicron Effect: Foreign Flights Won't Resume On Dec 15, Decision Later.

Output:

Omicron Effect: Foreign Flights Won't On Dec 15,

Click me to see the sample solution

**65.** Write a Python program to shift the decimal digits n places to the left, wrapping the extra digits around. If shift > the number of digits of n, reverse the string. Go to the editor

Input:

n = 12345 and shift = 1

Output:

Result = 23451

Input:

n = 12345 and shift = 2

Output:

Result = 34512

Input:

n = 12345 and shift = 3

Output:

Result = 45123

Input:

n = 12345 and shift = 5

Output:

Result = 12345

Input:

n = 12345 and shift = 6

Output:

Result = 54321

Click me to see the sample solution

**66.** Write a Python program to find the indices of the closest pair from a list of numbers. Go to the editor

Input: [1, 7, 9, 2, 10]

Output:

[0, 3]

Input: [1.1, 4.25, 0.79, 1.0, 4.23]

Output:

[4, 1]

Input: [0.21, 11.3, 2.01, 8.0, 10.0, 3.0, 15.2]

Output:

[2, 5]

Click me to see the sample solution

**67.** Write a Python program to find a string which, when each character is shifted (ASCII incremented) by shift, gives the result. Go to the editor

Input:

Ascii character table

Shift = 1

Output:

@rbhhbg`q`bsdqs`akd

Input:

Ascii character table

Shift = -1

Output:

Btdjj!dibsbdufs!ubcmf

Click me to see the sample solution

**68.** Write a Python program to find all 5's in integers less than n that are divisible by 9 or 15. Go to the editor

Input:

Value of n = 50

Output:

[[15, 1], [45, 1]]

Input:

Value of n = 65

Output:

[[15, 1], [45, 1], [54, 0]]

Input:

Value of n = 75

Output:

[[15, 1], [45, 1], [54, 0]]

Input:

Value of n = 85

Output:

[[15, 1], [45, 1], [54, 0], [75, 1]]

Input:

Value of n = 150

Output:

[[15, 1], [45, 1], [54, 0], [75, 1], [105, 2], [135, 2]]

Click me to see the sample solution

**69.** Write a Python program to create a new string by taking a string, and word by word rearranging its characters in ASCII order. Go to the editor

Input: Ascii character table

Output:

Aciis aaccehrrt abelt

Input: maltos won

Output:

almost now

Click me to see the sample solution

**70.** Write a Python program to find the first negative balance from a given a list of numbers which represent bank deposits and withdrawals. Go to the editor

Input:

[[12, -7, 3, -89, 14, 88, -78], [-1, 2, 7]]

Output:

[-81, -1]

Input:

[[1200, 100, -900], [100, 100, -2400]]

Output:

[None, -2200]

Click me to see the sample solution

**71.** Given a list of numbers and a number to inject, write a Python program to create a list containing that number in between each pair of adjacent numbers. Go to the editor

Input: [12, -7, 3, -89, 14, 88, -78, -1, 2, 7]

Separator: 6

Output:

[12, 6, -7, 6, 3, 6, -89, 6, 14, 6, 88, 6, -78, 6, -1, 6, 2, 6, 7]

Input: [1, 2, 3, 4, 5, 6]

Separator: 9

Output:

[1, 9, 2, 9, 3, 9, 4, 9, 5, 9, 6]

Click me to see the sample solution

**72.** Write a Python program to find the indices of three numbers that sum to 0 in a given list of numbers. Go to the editor

Input: [12, -7, 3, -89, 14, 4, -78, -1, 2, 7]

Output:

[1, 2, 5]

Input: [1, 2, 3, 4, 5, 6, -7]

Output:

[2, 3, 6]

Click me to see the sample solution

**73.** Write a Python program to find a substring in a given string contains a vowel between two consonants. Go to the editor

Input: Hello

Output:

Hel

Input: Sandwhich

Output:

San

Input: Python

Output:

hon

Click me to see the sample solution

**74.** Write a Python program to find a string consisting of space-separated characters with given counts. Go to the editor

Input: {'f': 1, 'o': 2}

Output:

f o o

Input: {'a': 1, 'b': 1, 'c': 1}

Output:

a b c

Click me to see the sample solution

**75.** Write a Python program to reorder numbers from a give array in increasing/decreasing order based on whether the first plus last element is odd/even. Go to the editor

Reorder numbers of a give array in increasing/decreasing order based on whether the first plus last element is odd/even.:

Input:

[3, 7, 4]

Output:

[3, 4, 7]

Input:

[2, 7, 4]

Output:

[7, 4, 2]

Input:

[1, 5, 6, 7, 4, 2, 8]

Output:

[1, 2, 4, 5, 6, 7, 8]

Input:

[1, 5, 6, 7, 4, 2, 9]

Output:

[9, 7, 6, 5, 4, 2, 1]

Click me to see the sample solution

**76.** Write a Python program to find the index of the largest prime in the list and the sum of its digits. Go to the editor

Input: [3, 7, 4]

Output:

[1, 7]

Input: [3, 11, 7, 17, 19, 4]

Output:

[4, 10]

Input: [23, 17, 201, 14, 10473, 43225, 421, 423, 11, 10, 2022, 342157]

Output:

[6, 7]

Click me to see the sample solution

**77.** Write a Python program to convert GPAs to letter grades according to the following table: Go to the editor

GPAs | Grades |
---|---|

4.0: | A+ |

3.7: | A |

3.4: | A- |

3.0: | B+ |

2.7: | B |

2.4: | B- |

2.0: | C+ |

1.7: | C |

1.4: | C- |

below: | F |

[4.0, 3.5, 3.8]

Output:

['A+', 'A-', 'A']

Input:

[5.0, 4.7, 3.4, 3.0, 2.7, 2.4, 2.0, 1.7, 1.4, 0.0]

Output:

['A+', 'A+', 'A-', 'B+', 'B', 'B-', 'C+', 'C', 'C-', 'F']

Click me to see the sample solution

**78.** Write a Python program to find the two closest distinct numbers in a given a list of numbers. Go to the editor

Input:

[1.3, 5.24, 0.89, 21.0, 5.27, 1.3]

Output:

[5.24, 5.27]

Input:

[12.02, 20.3, 15.0, 19.0, 11.0, 14.99, 17.0, 17.0, 14.4, 16.8]

Output:

[14.99, 15.0]

Click me to see the sample solution

**79.** Write a Python program to find the largest negative and smallest positive numbers (or 0 if none). Go to the editor

Input:

[-12, -6, 300, -40, 2, 2, 3, 57, -50, -22, 12, 40, 9, 11, 18]

Output:

[-6, 2]

Input:

[-1, -2, -3, -4]

Output:

[-1, 0]

Input:

[1, 2, 3, 4]

Output:

[0, 1]

Input:

[]

Output:

[0, 0]

Click me to see the sample solution

**80.** Write a Python program to round each float in a given list of number up to the next integer and return the running total of the integer squares. Go to the editor

Input: [2.6, 3.5, 6.7, 2.3, 5.6]

Output:

[9, 25, 74, 83, 119]

Input: [301.1, 401.4, -23.1, 13554122.0, 10201.0101, 10000000.0]

Output:

[91204, 252808, 253337, 183714223444221, 183714327525025, 283714327525025]

Click me to see the sample solution

**81.** Write a Python program to calculate the average of the numbers a through b ( b not included ) rounded to nearest integer, in binary (or -1 if there are no such numbers). Go to the editor

Input:

4 , 7

Output:

0b101

Input:

11 , 19

Output:

0b1110

Click me to see the sample solution

**82.** Write a Python program to find the sublist of numbers from a given list of numbers with only odd digits in increasing order. Go to the editor

Input:

[1, 3, 79, 10, 4, 2, 39]

Output:

[1, 3, 39, 79]

Input:

[11, 31, 40, 68, 77, 93, 48, 1, 57]

Output:

[1, 11, 31, 57, 77, 93]

Input:

[9, -2, 3, 4, -2, 0, 2, -3, 8, -1]

Output:

[-3, -1, 3, 9]

Click me to see the sample solution

**83.** A string is happy if every three consecutive characters are distinct. Write a Python program to find two indices making a given string unhappy. Go to the editor

Input:

Python

Output:

None

Input:

Unhappy

Output:

[4, 5]

Input:

Find

Output:

None

Input:

Street

Output:

[3, 4]

Click me to see the sample solution

**84.** Write a Python program to find the index of the matching parentheses for each character in a given string. Go to the editor

Input: ()(())

Output:

[1, 0, 5, 4, 3, 2]

Input: ()()()

Output:

[1, 0, 3, 2, 5, 4]

Input: ((()))

Output:

[5, 4, 3, 2, 1, 0]

Click me to see the sample solution

**85.** Write a Python program to find an increasing sequence consisting of the elements of the original list. Go to the editor

Input:

[1, 3, 79, 10, 4, 2, 39]

Output:

[1, 2, 3, 4, 10, 39, 79]

Input:

[11, 31, 40, 68, 77, 93, 48, 1, 57]

Output:

[1, 11, 31, 40, 48, 57, 68, 77, 93]

Input:

[9, -2, 3, 4, -2, 0, 2, -3, 8, -1]

Output:

[-3, -2, -1, 0, 2, 3, 4, 8, 9]

Click me to see the sample solution

**86.** Write a Python program to find the vowels from each of the original texts (y counts as a vowel at the end of the word) from a given list of strings. Go to the editor

Input: ['w3resource', 'Python', 'Java', 'C++']

Output:

['eoue', 'o', 'aa', '']

Input: ['ably', 'abruptly', 'abecedary', 'apparently', 'acknowledgedly']

Output:

['ay', 'auy', 'aeeay', 'aaey', 'aoeey']

Click me to see the sample solution

**87.** Write a Python program to find a valid substring of a given string that contains matching brackets, at least one of which is nested. Go to the editor

Input:

]][][[]]]

Output:

[[]]

Input:

]]]]]]]]]]]]]]]]][][][][]]]]]]]]]]][[[][[][[[[[][][][]][[[[[[[[[[[[[[[[[[

Output:

[[][][][]]

Click me to see the sample solution

**88.** Write a Python program to find an integer (n >= 0) with the given number of even and odd digits. Go to the editor

Input:

Number of even digits: 2 ,Number of odd digits: 3

Output:

22333

Input:

Number of even digits: 4 ,Number of odd digits: 7

Output:

22223333333

Click me to see the sample solution

**89.** Write a Python program to find all integers <= 1000 that are the product of exactly three primes. Each integer should represent as the list of its three prime factors. Go to the editor

Input: 10

Output:

[[2, 2, 2]]

Input: 50

Output:

[[2, 2, 2], [2, 2, 3], [2, 2, 5], [2, 2, 7], [2, 2, 11], [2, 3, 2], [2, 3, 3], [2, 3, 5], [2, 3, 7], [2, 5, 2], [2, 5, 3], [2, 5, 5], [2, 7, 2], [2, 7, 3], [2, 11, 2], [3, 2, 2], [3, 2, 3], [3, 2, 5], [3, 2, 7], [3, 3, 2], [3, 3, 3], [3, 3, 5], [3, 5, 2], [3, 5, 3], [3, 7, 2], [5, 2, 2], [5, 2, 3], [5, 2, 5], [5, 3, 2], [5, 3, 3], [5, 5, 2], [7, 2, 2], [7, 2, 3], [7, 3, 2], [11, 2, 2]]

Click me to see the sample solution

**90.** For each triple of eaten, need, stock write a Python program to get a pair of total appetite and remaining. Go to the editor

Input:

[[2, 5, 6], [3, 9, 22]]

Output:

[[7, 1], [12, 13]]

Input:

[[2, 3, 18], [4, 9, 2], [2, 5, 7], [3, 8, 12], [4, 9, 106]]

Output:

[[5, 15], [6, 0], [7, 2], [11, 4], [13, 97]]

Input:

[[1, 2, 3], [4, 5, 6]]

Output:

[[3, 1], [9, 1]]

Click me to see the sample solution

**91.** Write a Python program to find all n-digit integers that start or end with 2. Go to the editor

Input: 1

Output:

[2]

Input: 2

Output:

[12, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 32, 42, 52, 62, 72, 82, 92]

Input: 3

Output:

[102, 112, 122, 132, 142, 152, 162, 172, 182, 192, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259, 260, 261, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279, 280, 281, 282, 283, 284, 285, 286, 287, 288, 289, 290, 291, 292, 293, 294, 295, 296, 297, 298, 299, 302, 312, 322, 332, 342, 352, 362, 372, 382, 392, 402, 412, 422, 432, 442, 452, 462, 472, 482, 492, 502, 512, 522, 532, 542, 552, 562, 572, 582, 592, 602, 612, 622, 632, 642, 652, 662, 672, 682, 692, 702, 712, 722, 732, 742, 752, 762, 772, 782, 792, 802, 812, 822, 832, 842, 852, 862, 872, 882, 892, 902, 912, 922, 932, 942, 952, 962, 972, 982, 992]

Click me to see the sample solution

**92.** Write a Python program to start with a list of integers, keep every other element in place and otherwise sort the list. Go to the editor

Input:

[2, 5, 6, 3, 1, 4, 34]

Output:

[1, 5, 2, 3, 6, 4, 34]

Input:

[8, 0, 7, 2, 9, 4, 1, 2, 8, 3]

Output:

[1, 0, 7, 2, 8, 4, 8, 2, 9, 3]

Click me to see the sample solution

**93.** Write a Python program to find the closest palindrome from a given string. Go to the editor

Input:

cat

Output:

cac

Input:

madan

Output:

madam

Input:

radivider

Output:

radividar

Input:

madan

Output:

madam

Input:

abc

Output:

aba

Input:

racecbr

Output:

racecar

Click me to see the sample solution

**94.** Given a string consisting of whitespace and groups of matched parentheses, write a Python program to split it into groups of perfectly matched parentheses without any whitespace. Go to the editor

Input:

( ()) ((()()())) (()) ()

Output:

['(())', '((()()()))', '(())', '()']

Input:

() (( ( )() ( )) ) ( ())

Output:

['()', '((()()()))', '(())']

Click me to see the sample solution

**95.** Write a Python program to find a palindrome of a given length containing a given string. Go to the editor

Input: madam , 7

Output:

madaadam

Input: madam , 6

Output:

maddam

Input: madam , 5

Output:

maaaam

Input: madam , 3

Output:

maam

Input: madam , 2

Output:

mm

Input: madam , 1

Output:

aa

Click me to see the sample solution

**96.** Write a Python program to get the single digits in numbers sorted backwards and converted to English words. Go to the editor

Input:

[1, 3, 4, 5, 11]

Output:

['five', 'four', 'three', 'one']

Input:

[27, 3, 8, 5, 1, 31]

Output:

['eight', 'five', 'three', 'one']

Click me to see the sample solution

**97.** Write a Python program to find the following strange sort of list of numbers: the first element is the smallest, the second is the largest of the remaining, the third is the smallest of the remaining, the fourth is the smallest of the remaining, etc. Go to the editor

Input:

[1, 3, 4, 5, 11]

Output:

[1, 11, 3, 5, 4]

Input:

[27, 3, 8, 5, 1, 31]

Output:

[1, 31, 3, 27, 5, 8]

Input:

[1, 2, 7, 3, 4, 5, 6]

Output:

[1, 7, 2, 6, 3, 5, 4]

Click me to see the sample solution

**98.** Given a string consisting of groups of matched nested parentheses separated by parentheses, write a Python program to compute the depth of each group. Go to the editor

Input: (()) (()) () ((()()()))

Output:

[2, 2, 1, 3]

Input: () (()) () () () ()

Output:

[1, 2, 1, 1, 1, 1]

Input: (((((((()))))))) () (()) ((()()()))

Output:

[8, 1, 2, 3]

Click me to see the sample solution

**99.** Write a Python program to find a string such that, when three or more spaces are compacted to a '-' and one or two spaces are replaced by underscores, leads to the target. Go to the editor

Input: Python-Exercises

Output:

Python Exercises

Input: Python_Exercises

Output:

Python Exercises

Input: -Hello,_world!__This_is-so-easy!-

Output:

Hello, world! This is so easy!

Click me to see the sample solution

**100.** Write a Python program to find four positive even integers whose sum is a given integer. Go to the editor

Input:

n = 100

Output:

[94, 2, 2, 2]

Input:

n = 1000

Output:

[994, 2, 2, 2]

Input:

n = 10000

Output:

[9994, 2, 2, 2]

Input:

n = 1234567890

Output:

[1234567884, 2, 2, 2]

Click me to see the sample solution

Python Code Editor:

**More to Come !**

**Do not submit any solution of the above exercises at here, if you want to contribute go to the appropriate exercise page.**

Test your Python skills with w3resource's quiz

## Python: Tips of the Day

**Memory Management:**

getrefcount will show how many times an object is used in the memory. It's a fantastic tool that can be used for memory management in any program and it's very convenient too.

Getrefcount will calculate the object usage at a low level ByteCode so it can tend to be higher than expected. For instance when you print a value that value is actually processed multiple times in the background inside the print function itself and getrefcount also counts the instance when the value is called with getrefcount method itself. So, it's safe to say that the count will actually always be at least 1 time higher than expected.

Here is a code to show how many times alphanumeric characters are referenced in a random code:

import sys x_val = 20 x_val += 1 y_val = "Heritage" x = sys.getrefcount(x_val) y = sys.getrefcount(y_val) print(x, y, sep="\n")

Output:

10 4

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