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Python Data Structure Exercise for Beginners

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This data structure exercise is for beginners to understand and practice data structure in Python. Practice List, Set, Dictionary, and Tuple in Python. As you know data structure is widely to hold any data. To perform any programming tasks in Python, good knowledge of data structure is a must. When you complete each question, you get more familiar with List, Dictionary, set, and tuple.

What included in this data structure exercise?

Question covers list manipulation, dictionary, set and tuple methods.

  • The exercise contains 10 questions.
  • The solution provided for each question.
  • To solve each question, you need to learn the specific data structure topic.

Practice Questions using Code Editor

Let’s start the exercise.

Exercise Question 1: Given a two list. Create a third list by picking an odd-index element from the first list and even index elements from second.

For Example:

listOne = [3, 6, 9, 12, 15, 18, 21]
listTwo = [4, 8, 12, 16, 20, 24, 28]

Expected Outcome: [6, 12, 18, 4, 12, 20, 28]

listOne = [3, 6, 9, 12, 15, 18, 21]
listTwo = [4, 8, 12, 16, 20, 24, 28]
listThree = list()

oddElements = listOne[1::2]
print("Element at odd-index positions from list one")
print(oddElements)

EvenElement = listTwo[0::2]
print("Element at odd-index positions from list two")
print(EvenElement)

print("Printing Final third list")
listThree.extend(oddElements)
listThree.extend(EvenElement)
print(listThree)

Output:

Element at odd-index positions from list one
[6, 12, 18]
Element at odd-index positions from list two
[4, 12, 20, 28]
Printing Final third list
[6, 12, 18, 4, 12, 20, 28]

Exercise Question 2: Given an input list removes the element at index 4 and add it to the 2nd position and also, at the end of the list

For example: List = [54, 44, 27, 79, 91, 41]

Expected Outcome: [54, 44, 79, 27, 91, 41, 79].

sampleList = [34, 54, 67, 89, 11, 43, 94]

print("Origigal list ", sampleList)
element = sampleList.pop(4)
print("List After removing element at index 4 ", sampleList)

sampleList.insert(2, element)
print("List after Adding element at index 2 ", sampleList)

sampleList.append(element)
print("List after Adding element at last ", sampleList)

Output:

Origigal list  [34, 54, 67, 89, 11, 43, 94]
List After removing element at index 4  [34, 54, 67, 89, 43, 94]
List after Adding element at index 2  [34, 54, 11, 67, 89, 43, 94]
List after Adding element at last  [34, 54, 11, 67, 89, 43, 94, 11]

Exercise Question 3: Given a list slice it into a 3 equal chunks and rever each list

For Example: sampleList = [1, 2, 3, 4, 5, 6, 7, 8, 9]

Expected Outcome:

FirstList = [3, 2, 1]
sampleList = [6, 5, 4]
sampleList = [9, 8, 7]
sampleList = [11, 45, 8, 23, 14, 12, 78, 45, 89]
print("Origigal list ", sampleList)

length = len(sampleList)
chunkSize  = int(length/3)
start = 0
end = chunkSize
for i in range(1, 4, 1):
  indexes = slice(start, end, 1)
  listChunk = sampleList[indexes]
  print("Chunk ", i , listChunk)
  print("After reversing it ", list(reversed(listChunk)))
  start = end
  if(i != 2):
    end +=chunkSize
  else:
    end += length - chunkSize

Output:

Origigal list  [11, 45, 8, 23, 14, 12, 78, 45, 89]
Chunk  1 [11, 45, 8]
After reversing it  [8, 45, 11]
Chunk  2 [23, 14, 12]
After reversing it  [12, 14, 23]
Chunk  3 [78, 45, 89]
After reversing it  [89, 45, 78]

Exercise Question 4: Given a list iterate it and count the occurrence of each element and create a dictionary to show the count of each element

For example: list = [10, 20, 30, 10, 20, 40, 50]

Expected Outcome: dict = {10: 2, 20: 2, 30: 1, 40: 1, 50: 1}

sampleList = [11, 45, 8, 11, 23, 45, 23, 45, 89]
print("Origigal list ", sampleList)

countDict = dict()
for item in sampleList:
  if(item in countDict):
    countDict[item] += 1
  else:
    countDict[item] = 1
  
print("Printing count of each item  ",countDict)

Output:

Origigal list  [11, 45, 8, 11, 23, 45, 23, 45, 89]
Printing count of each item   {11: 2, 45: 3, 8: 1, 23: 2, 89: 1}

Exercise Question 5: Given a two list of equal size create a set such that it shows the element from both lists in the pair

For example:

firstList = [1, 2, 3, 4, 5]
secondList = [10, 20, 30, 40, 50]

Expected Output:

result = {(1, 10), (2, 20), (3, 30), (4, 40), (5, 50)}
firstList = [2, 3, 4, 5, 6, 7, 8]
print("First List ", firstList)

secondList = [4, 9, 16, 25, 36, 49, 64]
print("Second List ", secondList)

result = zip(firstList, secondList)
resultSet = set(result)
print(resultSet)

Output:

First List  [2, 3, 4, 5, 6, 7, 8]
Second List  [4, 9, 16, 25, 36, 49, 64]
Result is  {(6, 36), (8, 64), (4, 16), (5, 25), (3, 9), (7, 49), (2, 4)}

Exercise Question 6: Given a following two sets find the intersection and remove those elements from the first set

For Example:

firstSet = {10, 30, 40 , 60, 45}
secondSet = {20, 50, 10 , 40, 55}

Expected Outcome: firstSet = {30, 60, 45}

firstSet  = {23, 42, 65, 57, 78, 83, 29}
secondSet = {57, 83, 29, 67, 73, 43, 48}

print("First Set ", firstSet)
print("Second Set ", secondSet)

intersection = firstSet.intersection(secondSet)
print("Intersection is ", intersection)
for item in intersection:
  firstSet.remove(item)

print("First Set after removing common element ", firstSet)

Output:

First Set  {65, 42, 78, 83, 23, 57, 29}
Second Set  {67, 73, 43, 48, 83, 57, 29}

Intersection is  {57, 83, 29}
First Set after removing common element  {65, 42, 78, 23}

Exercise Question 7: Given two sets, Checks if One Set is Subset or superset of Another Set. if the subset is found delete all elements from that set

For Example:

firstSet = {27, 43, 34}
secondSet = {34, 93, 22, 27, 43, 53, 48}

Expected Outcome:

First set is sub set of second set
firstSet = {}
firstSet  = {57, 83, 29}
secondSet = {57, 83, 29, 67, 73, 43, 48}

print("First Set ", firstSet)
print("Second Set ", secondSet)

print("First set is subset of second set -", firstSet.issubset(secondSet))
print("Second set is subset of First set - ", secondSet.issubset(firstSet))

print("First set is Super set of second set - ", firstSet.issuperset(secondSet))
print("Second set is Super set of First set - ", secondSet.issuperset(firstSet))

if(firstSet.issubset(secondSet)):
  firstSet.clear()
  
if(secondSet.issubset(firstSet)):
  secondSet.clear()

print("First Set ", firstSet)
print("Second Set ", secondSet)

Output:

First Set  {57, 83, 29}
Second Set  {67, 73, 43, 48, 83, 57, 29}

First set is subset of second set - True
Second set is subset of First set -  False

First set is Super set of second set -  False
Second set is Super set of First set -  True

First Set  set()
Second Set  {67, 73, 43, 48, 83, 57, 29}

Exercise Question 8: Iterate a given list and Check if a given element already exists in a dictionary as a key’s value if not delete it from the list

Given:

rollNumber = [47, 64, 69, 37, 76, 83, 95, 97]
sampleDict ={'Jhon':47, 'Emma':69, 'Kelly':76, 'Jason':97}

Expected Outcome:

after removing unwanted elemnts from list [47, 69, 76, 97]
rollNumber  = [47, 64, 69, 37, 76, 83, 95, 97]
sampleDict  ={'Jhon':47, 'Emma':69, 'Kelly':76, 'Jason':97} 

print("List -", rollNumber)
print("Dictionary - ", sampleDict)

rollNumber[:] = [item for item in rollNumber if item in sampleDict.values()]
print("after removing unwanted elemnts from list ", rollNumber)

Output:

List - [47, 64, 69, 37, 76, 83, 95, 97]
Dictionary -  {'Jhon': 47, 'Emma': 69, 'Kelly': 76, 'Jason': 97}
[47, 69, 76, 97]
after removing unwanted elemnts from list  [47, 69, 76, 97]

Exercise Question 9: Given a dictionary get all values from the dictionary and add it in a list but don’t add duplicates

Given:

speed ={'jan':47, 'feb':52, 'march':47, 'April':44, 'May':52, 'June':53, 'july':54, 'Aug':44, 'Sept':54}

Expected Outcome: [47, 52, 44, 53, 54]

speed  ={'jan':47, 'feb':52, 'march':47, 'April':44, 'May':52, 'June':53,
          'july':54, 'Aug':44, 'Sept':54} 

print("Dictionary's values - ", speed.values())

speedList = list()
for item in speed.values():
  if item not in speedList:
    speedList.append(item)
print("unique list", speedList)

Output:

Dictionary's values -  dict_values([47, 52, 47, 44, 52, 53, 54, 44, 54])
unique list [47, 52, 44, 53, 54]

Exercise Question 10: Remove duplicate from a list and create a tuple and find the minimum and maximum number

For Example:

sampleList = [87, 45, 41, 65, 94, 41, 99, 94]

Expected Outcome:

unique items [87, 45, 41, 65, 99]
tuple (87, 45, 41, 65, 99)
min: 41
max: 99
sampleList = [87, 52, 44, 53, 54, 87, 52, 53]

print("Original list", sampleList)

sampleList = list(set(sampleList))
print("unique list", sampleList)

tuple = tuple(sampleList)
print("tuple ", tuple)

print("Minimum number is: ", min(tuple))
print("Maximum number is: ", max(tuple))

Output:

Original list [87, 52, 44, 53, 54, 87, 52, 53]
unique list [44, 52, 53, 54, 87]
tuple  (44, 52, 53, 54, 87)
Minimum number is:  44
Maximum number is:  87

 

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Comments

  1. Q2 Minor error in the wording. You ask to remove the ‘element at index 4’ – given the example and the solution, this should either read ‘the fourth item in the list’ or ‘the element at index 3’. With the current wording, you should be throwing around 91, not 79.

    By the way, a belated thank you for your work on this site. It is providing very useful memory jogging and consolidation for what I have learned to date. I look forward to the numpy and subsequent exercises, which will be mostly breaking new ground for me.

    Reply

  2. Q3 My slightly different approach which pads the original list with None values if necessary to make it exactly divisible into equal thirds:
    def thirds_reversed(lst):
    rem = len(lst)%3
    if rem > 0:
    for i in range(3 – rem):
    lst.append(None)

    slice = int(len(lst)/3)
    thirds = []
    for i in range(3):
    third = lst[i*slice:(i+1)*slice]
    third.reverse()
    thirds.append(third)
    return(thirds)
    print(thirds_reversed([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]))

    [[4, 3, 2, 1], [8, 7, 6, 5], [None, 11, 10, 9]]

    Reply

  3. Q4. Purely a matter of personal taste, but I prefer the dict’s setdefault method to testing whether the dict currently contains the term. my solution is therefore:

    hopkins = [“Not”, “I’ll”, “not”, “carrion”, “comfort”, “Despair”, “not”, “feast”, “on”, “thee”]
    dic = {}
    for w in hopkins:
    dic.setdefault(w.lower(), 0)
    dic[w.lower()] += 1
    print(dic)
    {‘not’: 3, “i’ll”: 1, ‘carrion’: 1, ‘comfort’: 1, ‘despair’: 1, ‘feast’: 1, ‘on’: 1, ‘thee’: 1}

    (And I hope these ‘pre’ tags do what I expect !?!)

    Reply

  4. Q6 – Or slightly more succinctly in one line:

    setA = setA.difference(setA.intersection(setB))

    Reply

  5. Q7 – Slight typo in the Expected Outcome which shows “firstSet = {}” (curly braces), which I must admit is what I was anticipating.
    Having read about sets but not having worked with them, I was puzzled as to why my solution was showing “firstSet = set()” (set prefix and round brackets) instead. It was only when I checked against your solution that I discovered we had done essentially the same and obtained the same result! Please amend the expected outcome line to show the correct result and possibly spare others the several minutes of head-scratching I experienced.
    I now realise that set() is how you would declare an empty set rather than as {} to differentiate it from an empty dictionary, hence that result. So at least the head-scratching resulted in a little more learning.

    Reply

  7. sampleList = [1, 2, 3, 4, 5, 6, 7, 8, 9]
    a = sampleList[:3]
    b = sampleList[3:6]
    c = sampleList[6:9]
    a.reverse()
    b.reverse()
    c.reverse()
    print(a)
    print(b)
    print(c)

    Reply

  8. please solve this problem
    Scenario
    You are required to design the data structure to display the individual player stats for cricket players. A player may have represented more than one team and may have played in more than one format such as Test, ODI and T20.
    Problem Statement
    Create a list of different data fields and use appropriate Python data types to represent each of them

    Reply

  9. Q2

    List = [34, 54, 67, 89, 11, 43, 94]
    List[2], List[3], List[4] = List[4], List[2], List[3]
    List.append(List[2])
    print(List)

    Reply

  10. Q3

    sampleList = [11, 45, 8, 23, 14, 12, 78, 45, 89]
    c_size = len(sampleList) // 3
    print(“”, sampleList[c_size – 1::-1], “\n”,sampleList[(c_size * 2) – 1:c_size – 1:-1],
    “\n”,sampleList[:(c_size * 2) – 1:-1])

    Reply

  12. Q6

    firstSet = {23, 42, 65, 57, 78, 83, 29}
    secondSet = {57, 83, 29, 67, 73, 43, 48}

    print(firstSet – secondSet)

    Reply

  13. Q9 as variant

    speed ={‘jan’:47, ‘feb’:52, ‘march’:47, ‘April’:44, ‘May’:52, ‘June’:53, ‘july’:54, ‘Aug’:44, ‘Sept’:54}
    print(list(set(speed.values())))

    Reply

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