Can you tell if an array is a view of another?

Question

Do numpy arrays keep track of their "view status"?

import numpy
a = numpy.arange(100)
b = a[0:10]
b[0] = 100
print a[0]
# 100 comes out as it is a view
b is a[0:10]
# False (hmm how to ask?)

What I am looking for is numpy.isview() or something.

I want this for code profiling to be sure that I am doing things correctly and getting views when I think I am.

Answer 1

the array also has a base attribute:

a = np.arange(10)
print a.base
None

b = a[2:9]
print b.base is a
True

c = b[:2]
print c.base is b
True
print c.base is a
False

Answer 2

ndarray.flags.owndata tells you whether the array owns its data. In your example:

In [18]: a.flags.owndata
Out[18]: True

In [19]: b.flags.owndata
Out[19]: False

It's clearly not as precise as what you're asking, but it's the best that I know of.