# Programming DSA using Python Nptel Week 4 Assignment Answers

Are you looking for the Programming, Data Structures and Algorithms using Python NPTEL Week 4 Assignment Answers 2024? You’re in the right place! This guide provides detailed solutions to the Week 4 assignment questions, covering key concepts in Python programming, data structures, and algorithms.

## Programming DSA using Python Week 4 Assignment Answers (July-Dec 2024)

Q1Consider the following Python function.

def mystery(l):
if l == []:
return(l)
else:
return(mystery(l[1:])+l[:1])

What does mystery([22,14,19,65,82,55]) return?

Q2.What is the value of pairs after the following assignment?
pairs = [ (x,y) for x in range(4,1,-1) for y in range(5,1,-1) if (x+y)%3 == 0 ]

These are Programming DSA using Python Week 4 Assignment Answers

Q3. Consider the following dictionary.
wickets = {“Tests”:{“Bumrah”:[3,5,2,3],”Shami”:[4,4,1,0],”Ashwin”:[2,1,7,4]},”ODI”:{“Bumrah”:[2,0],”Shami”:[1,2]}}
Which of the following statements does not generate an error?
wickets[“ODI”][“Ashwin”][0:] = [4,4]
wickets[“ODI”][“Ashwin”].extend([4,4])
wickets[“ODI”][“Ashwin”] = [4,4]
wickets[“ODI”][“Ashwin”] = wickets[“ODI”][“Ashwin”] + [4,4]

Q4. Assume that hundreds has been initialized as an empty dictionary:
hundreds = {}
Which of the following generates an error?
hundreds[“Tendulkar, international”] = 100
hundreds[“Tendulkar”] = {“international”:100}
hundreds[(“Tendulkar”,”international”)] = 100
hundreds[[“Tendulkar”,”international”]] = 100

These are Programming DSA using Python Week 4 Assignment Answers

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## Programming DSA using Python Week 4 Assignment Answers (JULY-DEC 2023)

Course Name: Programming Data Structure And Algorithms Using Python

These are Programming DSA using Python Week 4 Assignment Answers

### Quiz

Q1) Consider the following Python function.
def mystery(l):
if l == []:
return(l)
else:
return(l[-1:]+mystery(l[:-1]))
What does mystery([23,35,19,58,93,46]) return?

Answer: [46, 93, 58, 19, 35, 23]

Q2) What is the value of pairs after the following assignment?
pairs = [ (x,y) for x in range(6,1,-1) for y in range(3,1,-1) if (x+y)%2 == 0 ]

Answer: [(6,2), (5,3), (4,2), (3,3), (2,2)]

Q3) Consider the following dictionary.
goals = {“Country”:{“Ronaldo”:123,”Messi”:103,”Pele”:83},”Club”:{“Ronaldo”:[512,51,158],”Pele”:[604,49,26]}}
Which of the following statements does not generate an error?

goals[“Club”][“Messi”][0:] = [496,71,145]
goals[“Club”][“Messi”].extend([496,71,145])
goals[“Club”][“Messi”] = [496,71,145]
goals[“Club”][“Messi”] = goals[“Club”][“Messi”] + [496,71,145]

Q4) Assume that wickets has been initialized as an empty dictionary:
wickets = {}
Which of the following generates an error?

wickets[“Muralitharan, tests”] = 800
wickets[“Muralitharan”] = {“tests”:800}
wickets[(“Muralitharan”,”tests”)] = 800
wickets[[“Muralitharan”,”tests”]] = 800

### Assignment

Question 1
Write a Python function histogram(l) that takes as input a list of integers with repetitions and returns a list of pairs as follows:
for each number n that appears in l, there should be exactly one pair (n,r) in the list returned by the function, where r is the number of repetitions of n in l.
the final list should be sorted in ascending order by r, the number of repetitions. For numbers that occur with the same number of repetitions, arrange the pairs in ascending order of the value of the number.

``````def histogram(l):
count,ans,k = 0,list(),[]
for i in range(len(l)):
index,count=i,0
for j in range(index,len(l)):
if l[index] == l[j] and l[index] not in k :
count =count + 1
k = k + [l[index]]
if (count != 0):
ans = ans + [(l[index], count)]
ans.sort()
ans=sorted(ans,key=lambda ans:ans[1])
return(ans)

ans = list()
studentdetails.sort()
coursedetails.sort()
for studentdet in studentdetails:
tuple,inlist = studentdet,list()
for cdetail in coursedetails:
intuple = cdetail
inlist.append(intuple)
tuple = tuple + (inlist,)
ans.append(tuple)
return(ans)``````

These are Programming DSA using Python Week 4 Assignment Answers

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## Programming DSA using Python Week 4 Assignment Answers (JAN-APR 2023)

Course Name: Programming Data Structure And Algorithms Using Python

These are Programming DSA using Python Week 4 Assignment Answers

### Quiz

Q1. Consider the following Python function.

``````def mystery(l):
if (l == []):
return(l)
else:
mid = len(l)//2
if (len(l)%2 == 0):
return l[mid-1:mid+1] + mystery(l[:mid-1]+l[mid+1:])
else:
return l[mid:mid+1] + mystery(l[:mid]+l[mid+1:])``````

What does mystery([22,14,19,65,82,55]) return?

Answer: [19, 65, 14, 82, 22, 55]

Q2. What is the value of triples after the following assignment?

``````triples = [ (x,y,z) for x in range(1,4) for y in range(2,5) for z in range(5,8) if x+y > z ]
``````

Answer: [(2, 4, 5), (3, 3, 5), (3, 4, 5), (3, 4, 6)]

These are Programming DSA using Python Week 4 Assignment Answers

Q3. Consider the following dictionary.

``marks = {"Quizzes":{"Mahesh":[3,5,7,8],"Suresh":[9,4,8,8],"Uma":[9,9,7,6]},"Exams":{"Mahesh":[37],"Uma":[36]}}``

Which of the following statements does not generate an error?
marks[“Exams”][“Suresh”].extend([44])
marks[“Exams”][“Suresh”] = [44]
marks[“Exams”][“Suresh”].append(44)
marks[“Exams”][“Suresh”][0:] = [44]

These are Programming DSA using Python Week 4 Assignment Answers

Q4. Assume that actor has been initialized as an empty dictionary:

``````actor = {}
``````

Which of the following generates an error?
actor[“Star Wars”] = [“Rey”,”Ridley”]
actor[“Star Wars, Rey”] = “Ridley”
actor[[“Star Wars”, “Rey”]] = “Ridley”
actor[(“Star Wars”, “Rey”)] = “Ridley”

Answer: c. actor[[“Star Wars”, “Rey”]] = “Ridley”

These are Programming DSA using Python Week 4 Assignment Answers

### Programming Assignment

Question

Write two Python functions as specified below. Paste the text for all three functions together into the submission window. Your function will be called automatically with various inputs and should return values as specified. Do not write commands to read any input or print any output.

You may define additional auxiliary functions as needed.
In all cases you may assume that the value passed to the function is of the expected type, so your function does not have to check for malformed inputs.
For each function, there are normally some public test cases and some (hidden) private test cases.
“Compile and run” will evaluate your submission against the public test cases.
“Submit” will evaluate your submission against the hidden private test cases. There are 10 private test cases, with equal weightage. You will get feedback about which private test cases pass or fail, though you cannot see the actual test cases.

1. We have a list of annual rainfall recordings of cities. Each element in the list is of the form (c,r) where c is the city and r is the annual rainfall for a particular year. The list may have multiple entries for the same city, corresponding to rainfall recordings in different years.Write a Python function rainaverage(l) that takes as input a list of rainfall recordings and computes the avarage rainfall for each city.

The output should be a list of pairs (c,ar) where c is the city and ar is the average rainfall for this city among the recordings in the input list. Note that ar should be of type float. The output should be sorted in dictionary order with respect to the city name.Here are some examples to show how rainaverage(l) should work.

2. A list in Python can contain nested lists. The degree of nesting need not be uniform. For instance [1,2,[3,4,[5,6]]] is a valid Python list. Write a Python function flatten(l) that takes a nonempty list of lists and returns a simple list of all the elements in the nested lists, flattened out. You can make use of the following function that returns True if its input is of type list.Here are some examples to show how flatten(l) should work.

Solution:

``````def rainaverage(l):
raindata = {}
for (c,r) in l:
if c in raindata.keys():
raindata[c].append(r)
else:
raindata[c] = [r]
outputlist = []
for c in sorted(raindata.keys()):
thisaverage = sum(raindata[c])/len(raindata[c])
outputlist.append((c,thisaverage))
return(outputlist)

def flatten(l):
if not(listtype(l)):
return([l])
flatlist = []
for e in l:
flatlist.extend(flatten(e))
return(flatlist)

def listtype(l):
return(type(l) == type([]))``````

These are Programming DSA using Python Week 4 Assignment Answers

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## Programming DSA using Python Week 4 Assignment Answers (JULY-DEC 2022)

Course Name: Programming Data Structure And Algorithms Using Python

These are Programming DSA using Python Week 4 Assignment Answers

Q1) Consider the following Python function.
def mystery (1):
if 1 == [] :
return (1)
else :
return(mystery (1[1 : ])+1[1])
What does mystery ([22, 14, 19, 65, 82,55]) return?

Answer: [55, 82, 65, 19, 14, 22]

These are Programming DSA using Python Week 4 Assignment Answers

Q2) What is the value of pairs after the following assignment?
pairs = [ (x,y) for x in range (4,1,-1) for y in range (5,1,-1) if (x+y)%3 ==0]

These are Programming DSA using Python Week 4 Assignment Answers

Q3) Consider the following dictionary.
wickets = {“Tests” : {“Bumrah” : [3,5,2,3], “Shami” : [4,4,1,0], “Ashwin” : [2,1,7,4]}, “ODI” : {“Bumrah” : [2, 0], “Shami” : [1,2]}}
Which of the following statements does not generate an error?

wickets [“ODI”][“Ashwin”][ : ] = [4,4]
wickets [“ODI”][“Ashwin”].extend ([4,4])
wickets [“ODI”][“Ashwin”] = [4,4]
wickets [“ODI”][“Ashwin”] = wickets [“ODI”][“Ashwin”] + [4,4]

These are Programming DSA using Python Week 4 Assignment Answers

Q4) Assume that hundreds has been initialized as an empty dictionary :
hundreds = {}
Which of the following generates an error?

hundreds [“Tendulkar, international”] = 100
hundreds [“Tendulkar”] = {“international” : 100}
hundreds [(“Tendulkar”, “international”)] = 100
hundreds [[“Tendulkar”, “international”]] = 100

Answer: hundreds [[“Tendulkar”, “international”]] = 100

These are Programming DSA using Python Week 4 Assignment Answers

### Programming Assignment Solution

Q1. Write two Python functions as specified below. Paste the text for both functions together into the submission window. Your function will be called automatically with various inputs and should return values as specified. Do not write commands to read any input or print any output.

Solution:

``````def frequency(l):
SET=set(l)
LIST=list(SET)
newl=list()
for a in LIST:
newl.append(l.count(a))
mi=min(newl)
ma=max(newl)
mil=[]
mal=[]
for b in range(len(newl)):
if newl[b]==mi:

mil.append(LIST[b])
if newl[b]==ma:

mal.append(LIST[b])
mil.sort()
mal.sort()
return(mil,mal)

def onehop(l):
ans=list()
l.sort()
for x in range(len(l)):
for y in range(len(l)):
if l[x]!=l[y]:
if l[x][1]==l[y][0]:
q=l[x][0]
w=l[y][1]
if q!=w:
t=[q,w]
t=tuple(t)
if t not in ans:
ans.append(tuple(t))
ans.sort()
return (ans)``````

These are Programming DSA using Python Week 4 Assignment Answers