Pengindeksan dan Penghirisan

###############################################
#         INDEXING
###############################################

'''
Positive Indexing:
H E L L O   W O R L D
0 1 2 3 4 5 6 7 8 9 10
'''

#Positive indexing
message = 'HELLO WORLD'
print ('Postive indexing:', message[0], message [1], message [2], message [3], message [4])  # H E L L O

'''
Here indexing starts with 0. Python is able to strip the string like array elements
Negative indexing
H   E   L   L   O
-5  -4 -3  -2  -1
'''

#Negative indexing
message1 = '  Hello'
print ('Negative Indexing:', message1[-1], message1[-2], message1[-3], message1[-4], message1[-5]) # o l l e H

'''
Length is always number of characters or elements in string. 
  - length > last element index
  - length = last index +1

when we define out of range indexing, string index out of range error would come
In the above example,
'''

print('Length of string:',len(message), len(message1))     # 11 , 7


###############################################
#         SLICING
###############################################

#Message[Start:Stop:Step]
print('\nSlicing 1 to 4th index elements of HELLO WORLD using message[1:5]:', message[1:5])
print('Slicing before 6th index elements of HELLO WORLD using message[:6]:', message[:6])
print('Slicing from 6th index elements of HELLO WORLD using message[6:]:', message[6:])
print('Slicing from 6th index elements of HELLO WORLD using message[6: 100]:', message[6:100])


# Slicing using negative index also possible
print('\nSlicing using negative indexing in HELLO WORLD using message[-11:5]:', message[-11:5])
# Here number 5 is STOP, it refers 5th index
print('Slicing using negative indexing in HELLO WORLD using message[-11:-4]:', message[-11:-4])

'''
Reversing the message contents can be done using step definition
message [5:-10:-1]
'''
print('\nSlicing in reverse order using step (message [5:-12:-1]):',message [5:-12:-1])
print('Slicing in reverse order only ROW(NI) from HELLO WORLD (message [-3:-7:-1]):',message [-3:-7:-1])
print('Slicing in reverse order only ROW(PI) from HELLO WORLD (message [8:4:-1]):',message [8:4:-1])

PS C:\Projects\PythonSuresh> python Class7.py
Postive indexing: H E L L O
Negative Indexing: o l l e H
Length of string: 11 7

Slicing 1 to 4th index elements of HELLO WORLD using message[1:5]: ELLO
Slicing before 6th index elements of HELLO WORLD using message[:6]: HELLO 
Slicing from 6th index elements of HELLO WORLD using message[6:]: WORLD
Slicing from 6th index elements of HELLO WORLD using message[6: 100]: WORLD

Slicing using negative indexing in HELLO WORLD using message[-11:5]: HELLO
Slicing using negative indexing in HELLO WORLD using message[-11:-4]: HELLO W

Slicing in reverse order using step (message [5:-12:-1]):  OLLEH
Slicing in reverse order only ROW(NI) from HELLO WORLD (message [-3:-7:-1]): ROW
Slicing in reverse order only ROW(PI) from HELLO WORLD (message [8:4:-1]): ROW