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Rows and Columns With Negative Indexes

Do you know how negative indexes are represented in Python? Remember from the Python tutorial? No? No worries, let's go through it again:

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Using Negative Single Index

  • Using negative indexing on 1-D array
  • Pass the negative index of the element in a square bracket [ ].

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  • Using negative indexing on 2-D array
  • Pass the negative index of the element in a square bracket [].
  • Try executing num_arr[-1][-2] in your notebook

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Negative Index Intervals

  • Now you have an idea about how index intervals work on a NumPy array.
  • You also have an idea about how negative indexing works on Python lists.
  • See the snippet shown here. Can you think of how to get the output in yellow box using negative indexing? Try doing this on your own first.

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  • The following code didn't give the correct solution. Can you figure out why?

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  • Here's the correct solution. Phew!

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