Add numpy brain tips for numpy.append

[wshanks]

Steps to reproduce

astroid currently does not account for numpy.append as mentioned in #664. An example of the problem is the following file:

import numpy as np
a = np.append([0], 0)
a = -a

which produces the following errors in pylint:

/tmp/test.py:3:4: E1130: bad operand type for unary -: tuple (invalid-unary-operand-type)
/tmp/test.py:3:4: E1130: bad operand type for unary -: list (invalid-unary-operand-type)

These errors are generated for pylint=1.7.2, astroid=1.5.3 and numpy=1.16.2. The errors are not generated for numpy=1.15.4.

[hippo91]

Thanks for the bug report @willsALMANJ.
The problems comes from the fact that the append function is not correctly inferred as a numpy.ndarray.
I'll try to add a brain for this function ASAP.

[hippo91]

@willsALMANJ just a few words to explain why your issue is not yet solved.
There is no need to add the function append into a numpy brain as this function is defined inside a standard python module inside numpy. The problem arises when astroid tries to infer the result of the call to append. By analyzing the source, astroid is aware that the result of append comes from the call to numpy's concatenate function. This function is defined inside the brain_numpy_core_multiarray astroid module and so should be correctly inferred.
I'am still investigating.