Question

Lab2: Processing Strings

Part#1 – Counting Vows

Assume s is a string of lower case characters.

Write a program that counts up the number of vowels contained in the string s. Valid vowels are: 'a', 'e', 'i', 'o', and 'u'. For example, if s = 'azcbobobegghakl', your program should print:

Number of vowels: 5

Part#2 – Counting Bobs

Assume s is a string of lower case characters.

Write a program that prints the number of times the string 'bob' occurs in s. For example, if s = 'azcbobobegghakl', then your program should print

Number of times bob occurs is: 2

Part#3 – Alphabetical Substrings

Assume s is a string of lower case characters.

Write a program that prints the longest substring of s in which the letters occur in alphabetical order. For example, if s = 'azcbobobegghakl', then your program should print

Longest substring in alphabetical order is: beggh

In the case of ties, print the first substring. For example, if s = 'abcbcd', then your program should print

Longest substring in alphabetical order is: abc

Note: This problem is fairly challenging. We encourage you to work smart. If you've spent more than a few hours on this problem, we suggest that you stop. If you have time, come back to this problem after you've had a break and cleared your head.

USE PYTHON TO CODE THE PROGRAM!!!

Answer 1

Part#1 – Counting Vows

vowels='aeiou'
s = input("Enter the string: ")

count=0
for ch in s:
if ch in vowels:
count+=1
print("Total number of vowels are:",count)

Jupyter Untitled1 Last Checkpoint: a few seconds ago (unsaved changes) File Edit Viewnr Cell Kenel Widgets Help In [1] vowels- aeiou input( Enter the string:") count-0 for ch in s: if ch in vowels: count+=1 print("Total number of vowels are:",count) Enter the string: azcbobobegghakl Total number of vowels are: 5 In [ J:

Part#2 – Counting Bobs

word='bob'
s = input("Enter the string: ")

count=0
for i in range(len(s)):
if s[i:i+3] == word:
count+=1
print("Number of times bob occurs is:",count)

In [4] word-'bob s input("Enter the string: ") count-0 for i in range(len(s)): if s[i:i+3] word: count+ 1 print("Total number of times word present in the string:",count) Enter the string: azcbobobegghakl Total number of times word present in the string: 2

Part#3 – Alphabetical Substrings

def longest_substring(s):
groups = []
cur_longest = ''
prev_char = ''
for c in s.lower():
if prev_char and c < prev_char:
groups.append(cur_longest)
cur_longest = c
else:
cur_longest += c
prev_char = c
return max(groups, key=len) if groups else s

s=input("Enter the string: ")
sub_string=longest_substring (s)
print("Longest substring in alphabetical order is:",sub_string)

In [6]: def longest_substring(s): groups1 cur longest = .. prev_char for c in s.lower) if prev_char and c <prev_char: groups. append (cur_longest) cur-longest = c else: cur-longest += c prev_char c return max (groups, key-len) if groups else s In [7]: s-input ("Enter the string: ") sub_string-longest_substring (s) print "Longest substring in alphabetical order is:", sub_string) Enter the string: azcbobobegghakl Longest substring in alphabetical order is: beggh In [8]: s-input ("Enter the string: " sub_string-longest_substring (s) print("Longest substring in alphabetical order is:", sub_string) Enter the string: abcbcd Longest substring in alphabetical order is: abc