Python Tuples and Lists Quiz

Introduction to Python

• Course revision
• Questions and answers provided

Q1

• Write a function Intersec(D1, D2) that takes two dictionaries D1 and D2 and returns a new dictionary with the common keys in D1 and D2.
• Example: D1 = {1:'a', 2:'b', 3:'c'} , D2 = {2:'x', 4:'y', 1:'z'} Intersec(D1, D2) => {1: ['a', 'z'], 2: ['b', 'x']}

Q1 Answer

• def Intersec(D1, D2):
• res = {}
• for i in D1:
• if i in D2:
• res[i] = [D1[i], D2[i]]
• return res
• D1 = {1:'a', 2:'b', 3:'c'}
• D2 = {2:'x', 4:'y', 1:'z'}
• print(Intersec(D1, D2))

Q2

• Write a function Round(n) that takes a float number n and returns n rounded to the nearest integer.
• Note: you are not allowed to use the round built-in function.
• Example: Round (3.5) => 4 , Round (2.2) => 2

Q2 Answer

• def Round(n):
• if n - int(n) >= 0.5:
• return int(n) + 1
• return int(n)
• print (Round(3.5))

Q3

• Consider a text file where each line contains 3 integers separated by commas. For each line, the 1st integer is at position 0, the 2nd integer is at position 1, and the 3rd integer is at position 2. A column of data is defined as all integers in the file with the same position.
• Write a function ColAvg(F) that takes a file name F of the above format and returns a list of the averages of each column.
• Example: numbers.txt
  • 3,2,6
  • 2,3,3
  • 1,10,15
  • ColAvg("numbers.txt") => [2, 5, 8]

Q3 Answer

• def ColAvg(F):
• fin = open(F,'r')
• res = [0,0,0]
• lines = fin.readlines()
• i = 0
• for line in lines:
• for num in line.split(','):
  • res[i] += int(num)
  • i += 1
  • i = 0
• for i in range(len(res)):
  • res[i] = int(res[i]/len(lines))
• return res
• print (ColAvg("numbers.txt"))

Q4

• Write a function missing(L, n) that takes a list L and an integer n. The list contains numbers from 1 to n except a missing number. Your function should return this missing number.
• Example: missing([1,2,4,5], 5) => [3] , missing([1,2,3,4,5], 6) => [6] , missing([1,2,4],6) =>[3,5,6]

Q4 Answer

• def missing(L, n):
• set1=set(L)
• L2=list(range(1,n+1))
• set2=set(L2)
• diff=list(set2-set1)
• return diff
• print(missing([1,2,4,5], 5))

Q5

• Write a function CountInList(L) that takes a list L to count the number of zeros, even and odd numbers from a list of numbers.
• Example: CountInList([0,33,25,64,58,0,66,94,23,47,45,0,29,28])
• Output:
  • Number of Zeros: 3
  • Number of evens: 5
  • Number of odds: 6

Q5 Answer

• def CountInList(L):
• count_zeros=0
• count_odd=0
• count_even=0
• for i in L:
  • if i==0:
    • count_zeros+=1
  • elif i%2==0:
    • count_even+=1
  • else:
    • count_odd+=1
• return count_zeros,count_even,count_odd
• zeros,evens,odds=CountInList([0,33,25,64,58,0,66,94,23,47,45,0,29,28])
• print("Number of Zeros: ", zeros)
• print("Number of evens: ", evens)
• print("Number of odds: ", odds)

Other Output Questions

• Provided code output as requested.

File Processing

• Introduction
• Opening a file
• Reading from a file
• Writing to files
• Closing a file
• Reading from the web

Test your knowledge about Python tuples and lists with this quiz. Questions cover tuple manipulation, list slicing, and the differences between these two data structures. Perfect for beginners looking to deepen their understanding of Python's data types.