String tutorials in Python ,String-based python interview questions

A string is a collection of chars, we can store multiple characters set into String.

The base Index of the String will be started from 0 to size-1 similar to LIST.but all elements of the String are connected with each other.
we can write String is single quote (' '),double quote (" ") and triple quote (""").
a= 'hello'  ;  //Single Quote String
a = "hello"  //Double quote String
a= """hello""" //Triple quote String
s = "hello"
s[0]= h
s[1]= e
s[2]=l
s[3]=l
s[4]=o
Example of String Program?

Q1) WAP to count the total vowel and consonant in String?
Solution:-
s = "hello"
c1=0
c2=0
for i in range(0,len(s)):
    if s[i]=='a' or s[i]=='e' or s[i]=='i' or s[i]=='o' or s[i]=='u':
        c1=c1+1
    else:
        c2=c2+1
print("total vowel is ",c1," total consonent is ",c2)     

Q2)  WAP to check that String is palindrome or not?

s= input("enter string")  #aaaaaa

size= len(s)-1
c=1
for i in range(0,(len(s))//2):
    if s[i]!=s[size-i]:
        c=0
        print("not pallindrom")
        break
if c==1:
    print("pallindrom")
Q3)  WAP to find max char in String?
Solution:-
s = "hellop"
max=s[0]
for i in range(1,len(s)):
    if max<s[i]:
        max=s[i]
print(max)     

Q)WAP to validate email?

Solution:-
s = "@abcg.mailcom"
atpos=0
dotpos=0
for i in range(0,len(s)):
    if s[i]=="@" :
        atpos=i

    if s[i]=="." :
        dotpos=i
    if atpos>0 and (dotpos-atpos)>=2:
     print("valid email id")
else:
    print("invalid email id")

Q) WAP to validate the mobile number?
Q) WAP to validate first name and last name?
Q) WAP to provide a weak password and a Strong password?

1234 //w
12345//w
S@$1234 //Strong
123s@$123 //Strong
Q) WAP to find the largest palindrome in String?
Q) WAP to find max char in each string in a word?
Q) WAP to replace white space with an underscore?
Q) WAP to count total upper case, lower case, number, special char in String?

s = "abCA@$_123"

sc=0

chkcase=0

for data in s:

    if data in('@','$','_','#','!'):

        sc=sc+1

    if ord(data)>=65 and ord(data)<=91:

        chkcase=chkcase+1

if len(s)>5 and sc>2 and chkcase>1:

    print("strong password")

else:

    print("weak password")

Q) WAP to reverse a string in words?

s= "C CPP DS Java PHP"  # C PPC  SD  avaJ  PHP

s = s + " "

x = []

data = ''

for i in range(0,len(s)):

    if s[i]!=' ':

        data = data+s[i]

    else:

        x.append(data)

        data=''

for i in range(0,len(x)):

    d = x[i]

    

    for j in range(len(d)-1,-1,-1):

        print(d[j],end='')

    print()  

Q 2) How to remove all duplicates from a given string?
Q 3) How to remove characters from the first String which are present in the second String? 

5) How to check if two strings are rotations of each other? (solution)

Write an efficient program to test if two given String is a rotation of each other or not, e.g. if the given String is "XYZ" and "ZXY" then your function should return true, but if the input is "XYZ" and "YXZ" then return false.

6) How to reverse a given String? (solution)

Write a program to reverse a String in C/Java/Python or choice of your programming language. You can write either the recursive or iterative solution. For example, if a given input is "abcd," then your function should return "dcba".

7) How to reverse String without recursion? (solution)

Same as the previous program, but you cannot use recursion, this time, you must solve this problem in C/Java/Python using iteration or loops. If you are not familiar with recursion and repetition, you can further check the Algorithms and Data Structures - Part 1 and 2 courses on Pluralsight. One of the better course to start with fundamental techniques to solve algorithms based problems.

string programming interview questions for java developers

8) How to print all permutation of a String? (solution)

Write an efficient program to print all permutations of a given String in Java/C/Python or any programming language of your choice. For example, if given input is "123" then your program should print all 6 permutations e.g. "123", "132", "213", "231", "312" and "321".

9) How to find the first non-repeating character in a given String? (solution)

Write a program in any programming language you to find the first non-repeated character in a given String, for example, if the given String is "Java" then the first non-repeated character is "J"

10) How to reverse the words in a given String sentence? (solution)

Write an efficient program in Java or C++ to reverse the words in a given String sentence. For example, if the input is "Java is best," then your program should print "best is Java". There is no restriction on preserving white space.

11) How to find the smallest substring in a given string containing all characters of another string? (solution)

Write an efficient function in C/C++ or Java to print the smallest substring in a given string containing all characters of another String. For example, if the given String is "this is a test string" and "tist", then the output should be "t stri".

12) How to check if two given String is the anagram of each other? (solution)

Write an efficient program in Java/C/C++ to check if two String is an anagram of each other. An anagram contains are of the same length and contains the same character, but in a different order, for example, "Army" and "Mary" is the anagram. Your program should return true if both Strings are the anagram, false otherwise

13) How do you check if a given String is Palindrome or not? (solution)

Write an efficient program in your favorite programming language to check if a Given a string is a palindrome, considering only alphanumeric characters and ignoring cases. For example,"121" is a palindrome, but "123" is not. Your function should return true if given String is a palindrome, false otherwise

14) How do you convert String to an integer?  (solution)

Implement atoi() like function in C/C++/Java to convert a string to an integer. Consider all possible cases e.g. positive and negative String, the presence of + or - character, etc. For example, if the given input String is "123" then your program should return 123 and if a given input is "+231" then your program should return 231. 

Predefine method of String in Python:-

Method	Description

Python String capitalize() Converts first character to Capital Letter

Python String center() Pads string with the specified character

Python String casefold() converts to case folded strings

Python String count() returns occurrences of a substring in a string

Python String endswith() Checks if String Ends with the Specified Suffix

Python String expandtabs() Replaces Tab character With Spaces

Python String encode() returns encoded string of given string

Python String find() Returns the index of the first occurrence of a substring

Python String format() formats string into the nicer output

Python String index() Returns Index of Substring

Python String isalnum() Checks Alphanumeric Character

Python String isalpha() Checks if All Characters are Alphabets

Python String isdecimal() Checks Decimal Characters

Python String isdigit() Checks Digit Characters

Python String isidentifier() Checks for Valid Identifier

Python String islower() Checks if all Alphabets in a String are Lowercase

Python String isnumeric() Checks Numeric Characters

Python String isprintable() Checks Printable Character

Python String isspace() Checks Whitespace Characters

Python String istitle() Checks for Titlecased String

Python String isupper() returns if all characters are uppercase characters

Python String join() Returns a Concatenated String

Python String ljust() returns a left-justified string of given width

Python String rjust() returns a right-justified string of given width

Python String lower() returns the lowercased string

Python String upper() returns an uppercased string

Python String swapcase() swap uppercase characters to lowercase; vice versa

Python String lstrip() Removes Leading Characters

Python String rstrip() Removes Trailing Characters

Python String strip() Removes Both Leading and Trailing Characters

Python String partition() Returns a Tuple

Python String maketrans() returns a translation table

Python String rpartition() Returns a Tuple

Python String translate() returns mapped charactered string

Python String replace() Replaces Substring Inside

Python String rfind() Returns the Highest Index of Substring

Python String rindex() Returns Highest Index of Substring

Python String split() Splits String from Left

Python String rsplit() Splits String From Right

Python String splitlines() Splits String at Line Boundaries

Python String startswith() Checks if String Starts with the Specified String

Python String title() Returns a Title Cased String

Python String zfill() Returns a copy of The String Padded With Zeros

Python String format_map() Formats the String Using Dictionary

Python any() Checks if any Element of an Iterable is True

Python all() returns true when all elements in iterable is true

Python ascii() Returns String Containing Printable Representation

Python bool() Converts a Value to Boolean

Python bytearray() returns an array of given byte size

Python bytes() returns an immutable bytes object

Python compile() Returns a Python code object

Python complex() Creates a Complex Number

Python enumerate() Returns an Enumerate Object

Python filter() constructs iterator from elements that are true

Python float() returns floating-point number from number, string

Python input() reads and returns a line of string

Python int() returns an integer from a number or string

Python iter() returns an iterator for an object

Python len() Returns Length of an Object

Python max() returns largest element

Python min() returns smallest element

Python map() Applies Function and Returns a List

Python ord() returns Unicode code point for Unicode character

Python reversed() returns reversed iterator of a sequence

Python slice() creates a slice object specified by range()

Python sorted() returns a sorted list from a given iterable

Python sum() Add items of an Iterable

Python zip() Returns an Iterator of Tuples