String¶

List of Programs¶

Q1. Write a Program To REVERSE content of the given String by using slice operator?

input: ashish
output: hsihsa

s = input('Enter Some String to Reverse:')
output = s[::-1]
print(output)
s ="ashish" #read -ve indexing then do

# print(s[:-7:-1])

print(s[5:1:-1])

if step value is zero are you moving forword or backword

Q2. Write a Program To REVERSE content of the given String by using reversed() function?

s = input("Enter Some String to Reverse:")
r = reversed(s)
print(r)

s = input("Enter Some String to Reverse:")
r = reversed(s)
print(r) # we are getting reversed object

output= ''.join(r)
print(output)

s = input("Enter Some String to Reverse:")
r = reversed(s)

for v in r:
    print(v,end='')

Q3. Write a Program to REVERSE content of given String By uing while loop?

s = input("Enter Some String to Reverse:")
output=''
n = len(s)-1
while(n>-1):
    output = output+s[n]
    n-=1
print(output)

Q4. Write a Program to REVERSE order of words present in the given String?

s = input("Enter Some String to Reverse:")
l = s.split()
l1=l[::-1]
output = ' '.join(l1)
print(output)

Q5. Write a Program to REVERSE internal contentvof each word?

s = input("Enter Some String to Reverse:")
l = s.split()
l1 = []
for word in l:
    l1.append(word[::py-1])
output = ' '.join(l1)
print(output)

Q6. Write a Program to REVERSE internal contentv of every second word present int the given string?

s = input("Enter Some String to Reverse:")
l = s.split()
l1 = []
i=0
while i<len(l):
    if i%2 == 0:
        l1.append(l[i])
    else:
        l1.append(l[i][::-1])
    i+=1
output = ' '.join(l1)
print(output)

s = "ashish bindra"
l = s.split()
l1=[]
for i,word in enumerate(l):
    if i%2==1:
        l1.append(l[i][::-1])
    else:
        l1.append(l[i])
print(l1)

s = "ashish bindra"
l = s.split()
l1=[l[i][::-1] if i%2==1 else l[i] for i,word in enumerate(l)]
l1

Q7. Write a Program to print the character present at even and odd index seperatly for givern string ?

1 st way¶

s = input("Enter Some String to Reverse:")
print('Character present at even index:')
i=0
while i<len(s):
    print(s[i])
    i+=2
print('Charater present at Odd Index:')
i=1
while i<len(s):
    print(s[i])
    i+=2

# 2nd way
s = input("Enter Some String to Reverse:")
print('Character present at Even Index:',s[0::2])
print('Character present at Even Index:',s[::2])
print('Character present at odd Index:',s[1::2])

Q8. Write a Program to merge charaters of 2 strings inti a single string by taking charater alternatively ?

# if strings are having same length

s1 = "RAVI"
s2 = "TEJA"
output=''
i,j=0,0
while i<len(s1) or j<len(s2):
    output = output + s1[i]+s2[j]
    i+=1
    j+=1
print(output)

Note : The above program can work if the lengths of 2 strings are same.

# if strings are having different length

s1 = input('Enter First String: ')
s2 = input('Enter Second String: ')
output=''
i,j=0,0
while i<len(s1) or j<len(s2):
    if i<len(s1):
        output = output + s1[i]
        i+=1
    if j<len(s2):
        output = output + s2[j]
        j+=1
print(output)

Q9. Write a Program to sort charaters of the strings, first alphabet symbols followed by digits?

input: B4A1D3
output: ABD134

s = 'B4A1D3'
alphabets = []
digits = []
for ch in s:
    if ch.isalpha():
        alphabets.append(ch)
    else:
        digits.append(ch)
output = ''.join(sorted(alphabets) + sorted(digits))
print(output)

# -----------------
# alternative way
# -----------------
s = 'B4A1D3'
alphabets = ''
digits = ''
for ch in s:
    if ch.isalpha():
        alphabets+=ch
    else:
        digits+=ch
output = ''
for ch in sorted(alphabets):
    output=output+ch
for ch in sorted(digits):
    output=output + ch
print(output)

Q10. Write a Program for the following requirment?

input: a4b3c2
output: aaaabbbcc

s = input('Enter some string where alphabet symbol should be followed by digit: ')
output = ''
for ch in s:
    if ch.isalpha():
        x = ch
    else:
        d = int(ch)
        output = output + x*d
print(output)

Q11. WAP for the following requirment

input: aaaabbbccz
output: 4a3b2c1z

s = 'aaaabbbccz'
output = ''
previous = s[0]
c=1
i=1
while i<len(s):
    if s[i] == previous:
        c=c+1
    else:
        output = output+str(c)+previous
        previous = s[i]
        c = 1
    if i == len(s) - 1:
        output = output+str(c) + previous
    i = i+1
print(output)

# s = 'aaaabbbccz'
# output = ''
# global p
# p =''
# c = 1
# for i in s
# if p == i
# c+=1
# else
# output = output + c
# p = i
# c = 1

Q12. Write a Program for the following requirment?

input: a4k3b2
output: aekndb In this example the following two functions are required to use

ord(): To find unicode value for the given character eg:
- ord('a') --> 97
chr(): To find corresponding character for the given unicode value
- chr(98) --> b

s = 'a4k3b2'
output = ''
for ch in s:
    if ch.isalpha():
        x= ch
        output = output + ch
    else:
        d = int(ch)
        newc = chr(ord(x) + d)
        output = output + newc
print(output)

Q13. Write a program to remove duplicate characters from the given input string?

input: aaaavvvhhhjjj
output: avhj

# 1st way

# --------

s='AAAAZZZZZBCHGGJBBCCBHGFFCSSSFVA'
output=''

for ch in s:
    if ch not in output:
        output = output + ch
print(output)

# 2nd way

# --------

s='AAAAZZZZZBCHGGJBBCCBHGFFCSSSFVA'
l=[]
for ch in s:
    if ch not in l:
        l.append(ch)
output = ''.join(l)
print(output)

# 3rd way by using set (but no gurantee for the order)

s='AAAAZZZZZBCHGGJBBCCBHGFFCSSSFVA'
s1 = dict.fromkeys(s).keys()
output =''.join(s1)
print(output,type(s1))

Q14. Program to find the number of occurrences of each character present in the given string with count() method

# By using cout() method and list

s='AAAAZZZZZBCHGGJBBCCBHGFFCSSSFVA'

l = []
for ch in s:
    if ch not in l:
        l.append(ch)
for ch in sorted(l):
    print(f'{ch} occurrs {s.count(ch)} times')
s = input("enter any string ")
s1 = set(s)
for ch in sorted(s1):
    print(f'{ch} occurrs {s.count(ch)} times')

Q15. Program to find the number of occurrences of each character present in the given string without sing count() method

s='AAAAZZZZZBCHGGJBBCCBHGFFCSSSFVA'
d ={}

for ch in s:
    d[ch] = d.get(ch,0) + 1
for k,v in d.items():
    print(f'{k} occurrs {v} times')
print()

# for sorting propose

for k,v in sorted(d.items()):
    print(f'{k} occurrs {v} times')

Q16.Write a Program to find the number of occurrences of each vowel present in the given string?

s = input('Enter some string to search for vowels:')
v = ['a','e','i','o','u','A','E','I','O','U']
d = {}

for ch in s:
    if ch in v:
        d[ch] = d.get(ch,0) + 1
for k,v in sorted(d.items()):
    print(f'{k} occures {v} times')

Q17.Write a Program to check whether the given two strings are anagrams or not? Two strings are said to be anagrams iff both are having same content irrespective of characters position.

e.g

lazy and zaly
SILENT and LISTEN
TRIANGLE and INTEGRAL

s1 = input("Enter first string: ")
s2 = input("Enter second string: ")
if(sorted(s1) == sorted(s2)):
    print("The string are anagrams.")
else:
    print("The strings are't anagrams.")

Q18.Write a Program to check whether the strings is palindrome or not?

eg. level, malayalam, eye,..

A string is said to be palindrome iff original string and its reversed strings are equal.

s = input("Enter Some string:")
if s == s[::-1]:
    print('The given string is palindrome')
else:
    print('The given string is not palindrome')

Q19. Program to generate words from the given input strings ny taking characters alternatively?

inputs: s1 = 'abcdefg'
        s2 = 'xyz'
        s3 = '12345'
output: ax1, by2, cz3, d4 ,es, f, g

s1 = 'abcdefg'
s2 = 'xyz'
s3 = '12345'

i=j=k=0
while i< len(s1) or j<len(s2) or k<len(s3):
    output = ''
    if i< len(s1):
        output = output + s1[i]
        i+=1
    if j< len(s2):
        output = output + s2[j]
        j+=1
    if k< len(s3):
        output = output + s3[k]
        k+=1
    print(output)

First convert the given string to “a11” i.e. write, character along with its frequency.
Then, change “a11” to “ab” because 11 is b in hexadecimal.
Then, finally reverse the string i.e “ba”.

Input: S = “abc” Output: 1c1b1a

input_string = "aabbcc"
frequecy = {}
for i in input_string:
    frequecy[i] = frequecy.get(i,0) + 1
for k,v in reversed(frequecy.items()):
    print(k)

input_string = "aabbcc"
frequecy = {}
for i in reversed(input_string):
    frequecy[i] = frequecy.get(i,0) + 1
print(frequecy)

import json
input_string = "aabbcc"
frequecy = {}
for i in reversed(input_string):
    frequecy[i] = frequecy.get(i,0) + 1
a = json.dumps(frequecy)
print(a)

# `Input: str = “geEks”`
# `Output: 1`

Either the first 2 characters can be converted to uppercase characters i.e. “GEEks” with 2 operations.
Or the third character can be converted to a lowercase character i.e. “geeks” with a single operation.

Input: str = “geek” Output: 0
The string is already in the specified forma