How to install Numpy on Windows 8, in pyvenv?

Question

I have a virtual environment set up (Pyvenv, Python 3.4), but after executing activate.bat and the command `pip install numpy`, i get an error stating "Unable to find vcvarsall.bat". I added `C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC` to the PATH variable, which contains the vcvarsall.bat file, yet the error still remains. What is the issue here?

Accepted Answer

You do not need to compile numpy on Windows, you can just download the binaries. The numpy team does not upload Windows binaries to pypi (an open github issue on the subject can be found here), and you will need to download them manually from an alternative site. This is quite easy:

`activate` your env and check if you have a 32 or 64 bit Python:

```
(myenv) c:\mypoject\> python -c "import platform; print(platform.architecture()[0])"
```

This should print `32bit` or `64bit`.

Download the correct numpy from here and save it somewhere, (i.e. `c:\downloads`).

For `64bit` download the `win-amd-64` versions, and for `32bit` use the `win32` versions.

For example, for my python 2.7, I would need to download `numpy-1.10.2+mkl-cp27-none-win32.whl`. Make sure you don't change the file name! `.whl` files needs some information from the file name to be correctly identified by the pip installer!

Having your env still activated, just use `pip` (which supports installing from `whl` files) to extract and install numpy:

```
(myenv) c:\mypoject\> pip install c:\downloads
umpy-1.10.2+mkl-cp27-none-win32.whl
```

That's it!

Update: edited to use pip + `.whl` instead of obsolete easy_install + `.exe` packages.

How to install Numpy on Windows 8, in pyvenv?

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