NumPy Array: Indexing & Slicing

Indexing

• Indexing is used for accessing the elements of an array.
• Numpy array indexing is similar to simple array indexing.
• You have to specify the index number of an array element to retrieve it.
• Let us understand this with some examples.

For accessing the first element of a NumPy array we have to use 0(zero) because indexes start with 0 in the NumPy array.

Here we are accessing the 5th element of the array.

Slicing

• Slicing is very similar to indexing.
• It is useful when you have to extract a sequence of elements.
• Here are a few examples for you to understand it better.

Extracting 2nd & 3rd element from the array. (Note that the left boundary is inclusive while the right boundary is exclusive)

If you don’t specify the left boundary it will take default value 0 for it.

If you don’t specify the right boundary it will take the length of the array for it. (Returns entire array starting from the left boundary)

• Don’t know how to create a NumPy array? Click here