我如何'强迫'python使用特定版本的模块？

Question

I'm new to python so I apologize if this has been answered elsewhere with tags I haven't thought of.

I'm trying to update numpy from the 1.6 version I have now to 1.8. I've installed numpy in my python site-packages when I call numpy it calls the old 1.6 version. I've tried looking for the root to numpy 1.6 so I can remove it but that leads to :-

import numpy
print numpy.__version__
print numpy.__file__
>>>
1.6.2
V:\Brian.140\Python.2.7.3\lib\site-packages\numpy\__init__.pyc

I've added the folder containing the module to the system path using:-

sys.path.append('C:/Python27/Lib/site-packages')

and I know this works as I can call other modules in this location with no errors, for example:-

import wx
import Bio

and

import nose

produce no errors. Why is this happening and how can I tell python which version of numpy to use?

Answer 1

You can also insert the directory to the beginning of the path, so you won't need to remove the old one:

sys.path.insert(1, 'C:/Python27/Lib/site-packages')

That won't work if you've already import your module. You can either import it after the sys.path.insert command, or use importlib.reload( module_name )

Answer 2

This is a very messy solution and probably shouldn't be encouraged but I found that if I remove the location of the old version of numpy from the system path I can call the version I want. The specific lines were:-

import sys
sys.path.append('C:/Python27/Lib/site-packages')
sys.path.remove('V:\\\Brian.140\\\Python.2.7.3\\\Lib\\\site-packages')
import numpy

Answer 3

Force python to use an older version of module (than what I have installed now) mentions a generic solution:

 import pkg_resources pkg_resources.require("numpy==`1.16.2") # modified to use specific numpy import numpy