String Manipulations
					=====================
What is String?
===============
	-> It is a character or group of characters must be enclosed with:
		either single quotes ('') or 
		double quotes ("") or 
		triple quotes (''' '''/""" """)
Note:
====
Like other high level programming languages,
	Python does not have character datatype.
-> The character data also considered as "string" in python

# string definition

str1 = 'a'
str2 = 'abc'
str3 = "b"
str4 = "bcde"
str5 = '''a'''
str6 = '''abcdef'''
str7 = """p"""
str8 = """Pqrst"""

print(type(str1),type(str2),type(str3))
print(type(str4),type(str5),type(str6))
print(type(str7),type(str8))

Q: Is it possible to define the multi-line string?
==================================================
Ans: yes

# Multi-line string
# multi-line string can always define with triple quotes
mlst = '''Hello
Good Evening.
Today, we are discussing about Strings
with multiple built-in functions.
'''

print(type(mlst))
print(mlst)

mlst1 = """
HI
This is Ravi
from Ashok IT
Teaching about Python fullstack
and Java fullstack.
"""

print(mlst1)

mlst2 = ('Python Fullstack'
         'which includes Core Python, Advanced Python, Frameworks, '
         'Libraries')

print(mlst2)

Q: Is it possible to place double quotes within double quotes or vice versa.
No.

a = "Python \"Full stack\" Development"
b = 'Python \'Full stack\' Development'
c = "Python 'full stack' development"
d = 'Java "full stack" development'

print(a)
print(b)
print(c)
print(d)

===================================================================
Accessing of Characters of the string:
======================================
1) Using Index
==============
-> Index ==> a number (integer)
Note:
=====
Python supports positive indexing and negative indexing also.
Syntax:
	string-data-name[index]

Positive Indexing
=================
-> In python, positive indexing can use to do the forward accessing (left to right) on the strings to get individual characters of the string.
-> Positive indexing can always start with '0' and end with 'l (total number of characters) - 1'

Ex: s = "Python"
here:
range of positive index values are ==> 0 to 5
s[0] ==> 'P'
s[1] ==> 'y'
s[2] ==> 't'
s[3] ==> 'h'
s[4] ==> 'o'
s[5] ==> 'n'

Negative Indexing:
==================
-> Negative Indexing can use to access the characters from right to left (reverse access).
-> Range of negative index ==> '-1 to - l (number of characters of the string)'

s[-1] ==> 'n'
s[-2] ==> 'o'
s[-3] ==> 'h'
s[-4] ==> 't'
s[-5] ==> 'y'
s[-6] ==> 'P'

# indexing
s = "Python"

# positive indexing
print(s[0])
print(s[1])
print(s[2])
print(s[3])
print(s[4])
print(s[5])

print(s[-1])
print(s[-2])
print(s[-3])
print(s[-4])
print(s[-5])
print(s[-6])

2) Using Slice operator
=======================
-> Slicing is defined as acquiring of the part of the string.
Ex: "Python Programming Language"
op ==> "Python"
op1 ==> "Program"
op2 ==> "Language"

Syntax:
	string-name[start:stop:step]

Here:
	start ==> start index (starting point for slicing)
	stop ==> stop index (stopping point for slicing)
	step ==> difference 

Note:
=====
1) If you want to do the slicing from first character (index 0) of the given string:
	Syntax:
		string[0:stop:step] or string[:stop:step]

2) stop value can always consider the '-1' from the given value.
3) default value for step ==> '1'
4) When you want to do the slicing till the last character:
Syntax:
	string[start: len(string)] or string[start:]

s = "Python Programming Language"

print(s[0:5])
print(s[0:6])
print(s[:6])
print(s[:6:1])
print(s[:6:])
print(s[19:len(s)])
print(s[19:])
print(s[0:len(s):3])
print(s[::3])
print(s[::])
print(s[::-1])


3) Using loop statements
========================
While loop:
==========
s = "Object Oriented Programming Language"

print("The Total number of characters of the string = ",len(s))

# here: the positive index range ==> 0 to 35
# negative index range ==> -1 to -36

# forward looping

i = 0
while i < len(s):
    print(s[i],end = " ")
    i += 1

print()

i = -1
while i >= -len(s):
    print(s[i],end = "  ")
    i -= 1
=========================================================
4) Using built-in functions