15

Why do we use numpy arrays in place of lists in python? What is the main difference between them?

Improve this question
2
  • 5
    What do you mean by array? Do you really mean arrays or did you want to say list ([1, 2, 3] is a list, not an array)? Commented Mar 6, 2016 at 10:37
  • 3
    If you actually mean arrays, please clarify. Commented Mar 6, 2016 at 10:49

1 Answer 1

Reset to default
12

Numpy arrays is a typed array, the array in memory stores a homogenous, densely packed numbers.

Python list is a heterogeneous list, the list in memory stores references to objects rather than the number themselves.

This means that Python list requires dereferencing a pointer every time the code needs to access the number. While numpy array can be processed directly by numpy vector operations, which makes these vector operations much faster than anything you can code with list.

The drawback of numpy array is that if you need to access single items in the array, numpy will need to box/unbox the number into a python numeric object, which can make it slow in certain situations; and that it can't hold heterogeneous data.

Improve this answer
Sign up to request clarification or add additional context in comments.

3 Comments

This is true of a list, but not of an array, which also exists in the standard library.
So @jonrsharpe are you saying that normal python arrays and Numpy arrays are essentially equal? Please describe your comment a bit more. Thank you
@MuhammadMuzammil I'm saying that a list is not the same thing as an array; it's not clear to me which the OP meant by "simple python array".

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.