Please refer to README for bulk of the instructions
Generally, pytorch GPU build should work fine on machines that don’t have a CUDA-capable GPU, and will just use the CPU. However, you can install CPU-only versions of Pytorch if needed with
The pip ways is very easy:
pip install http://download.pytorch.org/whl/cpu/torch-1.0.0-cp36-cp36m-linux_x86_64.whl pip install fastai
Just make sure to pick the correct torch wheel url, according to the needed platform, python and CUDA version, which you will find here.
The conda way is more involved. Since we have only a single fastai package that relies on the default
pytorchpackage working with and without GPU environment, if you want to install something custom you will have to manually tweak the dependencies. This is explained in detail here. So follow the instructions there, but replace
Also, please note, that if you have an old GPU and
pytorch fails because it can’t support it, you can still use the normal (GPU)
pytorch build, by setting the env var
CUDA_VISIBLE_DEVICES="", in which case pytorch will not try to check if you even have a GPU.
Jupyter notebook dependencies
fastai library doesn’t require the jupyter environment to work, therefore those dependencies aren’t included. So if you are planning on using
fastai in the jupyter notebook environment, e.g. to run the
fastai course lessons and you haven’t already setup the jupyter environment, here is how you can do it.
conda install jupyter notebook conda install -c conda-forge jupyter_contrib_nbextensions
Some users also seem to need this conda package to be able to choose the right kernel environment, however, most likely you won’t need this package.
conda install nb_conda
pip install jupyter notebook jupyter_contrib_nbextensions
If for any reason you don’t want to install all of
fastai’s dependencies, since, perhaps, you have limited disk space on your remote instance, here is how you can install only the dependencies that you need.
fastaiwithout its dependencies using either
# pip pip install --no-deps fastai # conda conda install --no-deps -c fastai fastai
The rest of this section assumes you’re inside the
fastaigit repo, since that’s where
setup.pyresides. If you don’t have the repository checked out, do:
git clone https://github.com/fastai/fastai cd fastai tools/run-after-git-clone
Next, find out which groups of dependencies you want:
python setup.py -q deps
You should get something like:
Available dependency groups: core, text, vision
You need to use at least the
Do note that the
depscommand is a custom
distutilsextension, i.e. it only works in the
Finally, install the custom dependencies for the desired groups.
For the sake of this demonstration, let’s say you want to get the core dependencies (
core), plus dependencies specific to computer vision (
vision). The following command will give you the up-to-date dependencies for these two groups:
python setup.py -q deps --dep-groups=core,vision
It will return something like:
Pillow beautifulsoup4 bottleneck dataclasses;python_version<'3.7' fastprogress>=0.1.18 matplotlib numexpr numpy>=1.12 nvidia-ml-py3 packaging pandas pyyaml requests scipy torch>=1.0.0 torchvision typing
which can be fed directly to
pip install $(python setup.py -q deps --dep-groups=core,vision)
Since conda uses a slightly different syntax/package names, to get the same output suitable for conda, add
python setup.py -q deps --dep-groups=core,vision --dep-conda
If your shell doesn’t support
$()syntax, it most likely will support backticks, which are deprecated in modern
bash. (The two are equivalent, but
$()has a superior flexibility). If that’s your situation, use the following syntax instead:
pip install `python setup.py -q deps --dep-groups=core,vision`
Manual copy-n-paste case:
If, instead of feeding the output directly to
conda, you want to do it manually via copy-n-paste, you need to quote the arguments, in which case add the
--dep-quoteoption, which will do it for you:
# pip: python setup.py -q deps --dep-groups=core,vision --dep-quote # conda: python setup.py -q deps --dep-groups=core,vision --dep-quote --dep-conda
So the output for pip will look like:
"Pillow" "beautifulsoup4" "bottleneck" "dataclasses;python_version<'3.7'" "fastprogress>=0.1.18" "matplotlib" "numexpr" "numpy>=1.12" "nvidia-ml-py3" "packaging" "pandas" "pyyaml" "requests" "scipy" "torch>=1.0.0" "torchvision" "typing"
pip selective dependency installation:
pip install --no-deps fastai pip install $(python setup.py -q deps --dep-groups=core,vision)
same for conda:
conda install --no-deps -c fastai fastai conda install -c pytorch -c fastai $(python setup.py -q deps --dep-conda --dep-groups=core,vision)
--dep-groupsargument to match your needs.
# show available dependency groups: python setup.py -q deps # print dependency list for specified groups python setup.py -q deps --dep-groups=core,vision # see all options: python setup.py -q deps --help
As explained in Development Editable Install, if you want to work on contributing to fastai you will also need to install the optional development dependencies. In addition to the ways explained in the aforementioned document, you can also install
fastai with developer dependencies without needing to check out the
To install the latest released version of
fastaiwith developer dependencies, do:
pip install "fastai[dev]"
To accomplish the same for the cutting edge master git version:
pip install "git+https://github.com/fastai/fastai#egg=fastai[dev]"
It’s highly recommended to use a virtual python environment for the
fastai project, first because you could experiment with different versions of it (e.g. stable-release vs. bleeding edge git version), but also because it’s usually a bad idea to install various python package into the system-wide python, because it’s so easy to break the system, if it relies on python and its 3rd party packages for its functionality.
There are several implementations of python virtual environment, and the one we recommend is
conda (anaconda), because we release our packages for this environment and pypi, as well.
conda doesn’t have all python packages available, so when that’s the case we use
pip to install whatever is missing.
You will find the instructions for installing conda on each platform here. Once you followed the instructions and installed anaconda, you’re ready to build you first environment. For the sake of this example we will use an environment name
fastai, but you can name it whatever you’d like it to be.
The following will create a
fastai env with python-3.6:
conda create -n fastai python=3.6
Now any time you’d like to work in this environment, just execute:
conda activate fastai
It’s very important that you activate your environment before you start the jupyter notebook if you’re using
Say, you’d like to have another env to test fastai with python-3.7, then you’d create another one with:
conda create -n fastai-py37 python=3.7
and to activate that one, you’d call:
conda activate fastai-py37
If you’d like to exit the environment, do:
To list out the available environments
conda env list
Also see bash-git-prompt which will help you tell at any moment which environment you’re in.