[Python] pyarrow needs to depend on numpy>=1.10 (not 1.9)

[asfimport]

The pyarrow package lists numpy >= 1.9 as a dependency in setup.py - however, it causes an exception at import time with numpy 1.9.

Repro steps:

{{$ pip install numpy==1.9
...
$ pip install pyarrow
...
$ python -c 'import pyarrow'
RuntimeError: module compiled against API version a but this version of numpy is 9
Traceback (most recent call last):
File "", line 1, in
File "/home/dima/envs/pyarrow-bug/lib/python2.7/site-packages/pyarrow/init.py", line 28, in
from pyarrow.lib import cpu_count, set_cpu_count
File "pyarrow/lib.pyx", line 40, in init pyarrow.lib (/arrow/python/build/temp.linux-x86_64-2.7/lib.cxx:62119)
ImportError: numpy.core.multiarray failed to import
}}

(Additionally, requirements.txt lists "numpy>=1.7" - though it doesn't look like it's used at all.)

Reporter: Dima Ryazanov / @dimaryaz
Assignee: Uwe Korn / @xhochy

_{Note: This issue was originally created as ARROW-1124. Please see the migration documentation for further details.}

[asfimport]

Uwe Korn / @xhochy:
I made a PR to update the dependency specification to >=1.10: #758

Actually for Python 2, we could build the wheel with NumPy 1.9 to support >=1.9 as a python 2 specification. @dimaryaz if there is a need for you to have 1.9 support for Python 2, feel free to make a PR that adds this dependency conditionally only for Python 2 and adjust the manylinux1 build script.

[asfimport]

Dima Ryazanov / @dimaryaz:
Oh, I don't actually need NumPy 1.9 support - but it's breaking Travis CI because the Python 2 environment comes with NumPy 1.9 pre-installed. Simply requiring 1.10 would fix that.

[asfimport]

Uwe Korn / @xhochy:
Issue resolved by pull request 758
#758