String Manipulations
====================
Accessing of characters of the string:
======================================
	1) Indexing
	2) Slicing
	3) Looping

for loop:
=========
Syntax:
	for iteration-variable in string:
		// loop body

Ex: string = "abcd"
for i in string:
	print(i)	#a b

string = "abcde"

print(string)
for i in string:
    print(i)
print(i)

================================================
# WAP TO ACCEPT A STRING AS AN INPUT AND PRINT ALL CHARACTERS OF THE STRING ALONG WITH ITS POSITIVE AND NEGATIVE INDEXES USING FOR LOOP.

string = input("Enter any string:")

index = 0

for r in string:
    print("The Character at positive index",index,"and at negative index",(index - len(string)),"is = ",r)
    index = index + 1
================================================
Math operations on Strings:
===========================
1) String Concatenation
=======================
	-> Joining of two or more strings into one main string is called as "String concatenation".
	-> String concatenation can be used to represent with: '+'
Ex: "str1" + "str2" + "str3"
 "str1str2" + "str3"
output = "str1str2str3"

str1 = "python "
str2 = "is "
str3 = "one of the "
str4 = "scripting "
str5 = "language"

s = str1 + str2 + str3 + str4 + str5

print("The concatenated string = ",s)

====================================================
# WAP TO CHECK WHETHER THE GIVEN STRING IS PALINDROME OR NOT.

"""
if a string is palindrome:
reverse of string == string ==> palindrome
otherwise: not palindrome
"""

string = input("Enter some string:")

reverseString = ""  # empty string

for i in string:
    reverseString = i + reverseString 

if reverseString == string:
    print("The given string is palindrome.")
else:
    print("The given string is not palindrome.")
============================================================
Note:
=====
Strings are immutable.
Once you can define, there is no modification allowed to that string variable.

str1 = "Python "
str2 = "is easy"

print("Before Modification:")
print(str1)
print(str2)

print("str1 address = ",id(str1))
print("str2 address = ",id(str2))

str1 = str1 + str2  # re-assignment

print("After the modification:")
print(str1)
print(str2)

print("str1 address = ",id(str1))
print("str2 address = ",id(str2))

2) String repetition
====================
when you want to repeat the string content for several number of times, we can use "string repetition".
Syntax:
	string-name * n
here:
	n ==> number of times

str1 = "Python "

result = str1 * 5

print(result)

======================================================
String Slicing:
===============
-> when we want to acquire the piece or part of the string, we can use "slicing".
-> slicing can be used to define with slice operator []
Syntax:
	string-name[start-index : stop-index : step-index]

s = "Python is Easy Language"

print(s[0:6:1])
# id the slicing need to start with first character of teh given string, then: start-index (0) is optional to specify in the slicing syntax.
print(s[:6:1])
# if the slicing is needed with the index difference of '1', then: step-index also optional here.
print(s[:6:])
print(s[:6])
print(s[:15:3])

print(s[15:23])
#suppose, the slicing is required till the last characcter of the string, then: stop-index is optional in the syntax.
print(s[15:])

# if no start index and also no stop-index but step-index is added
print(s[::1])
print(s[::])

# step-index as negative
print(s[::-1])  # reverse of the string

# start as negative
# stop as negative

print(s[-10:-1])
# start < stop

print(s[10:1:-1])
print(s[-1:-10:-1])