Explain slicing and indexing operations.

Slicing and Indexing operations :
  • Indexing operation allows to access a particular item in the sequence directly.
  • Slicing operation allows to retrieve a part of the sequence.
  • In slicing :
S[ StartNo : StopNo : Step ]
  • If the start no is omitted, Python will start at the beginning of the sequence.
  • If the stop no is omitted, Python will stop at the end of the sequence.
>>> a = [1,2,3,4]
>>> a[0:2] # take items 0-2, upper bound noninclusive
[1, 2]
>>> a[0:-1] #take all but the last
[1, 2, 3]
>>> a[1:4]
[2, 3, 4]
>>> a[::-1] # reverse the list
[4, 3, 2, 1]
>>> a[::2] # skip 2
[1, 3]

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