debian-pyenv-poetry post

content/post/20210822-debian-pyenv-poetry/index.md

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+title = "Setting up Python with Pyenv and Poetry on Debian"
+date = 2021-08-22T00:00:00
+lastmod = 2021-08-22T00:00:00
+draft = false
+
+# Authors. Comma separated list, e.g. `["Bob Smith", "David Jones"]`.
+authors = ["Carl Pearson"]
+
+tags = [""]
+
+summary = ""
+
+# Projects (optional).
+#   Associate this post with one or more of your projects.
+#   Simply enter your project's folder or file name without extension.
+#   E.g. `projects = ["deep-learning"]` references 
+#   `content/project/deep-learning/index.md`.
+#   Otherwise, set `projects = []`.
+projects = []
+
+# Featured image
+# To use, add an image named `featured.jpg/png` to your project's folder. 
+[image]
+  # Caption (optional)
+  caption = ""
+
+  # Focal point (optional)
+  # Options: Smart, Center, TopLeft, Top, TopRight, Left, Right, BottomLeft, Bottom, BottomRight
+  focal_point = "Center"
+
+  # Show image only in page previews?
+  preview_only = true
+
+
+categories = []
+
+# Set captions for image gallery.
+
+
++++
+
+## Pyenv
+
+[pyenv](https://github.com/pyenv/pyenv) is...
+
+On Debian, you can visit [pyenv-installer](https://github.com/pyenv/pyenv-installer) to install pyenv.
+
+Then, I had to add to my `.zshrc`:
+```zsh
+export PYENV_ROOT="$HOME/.pyenv"
+export PATH="$PYENV_ROOT/bin:$PATH"
+eval "$(pyenv init --path)"
+eval "$(pyenv init -)"
+```
+
+To install new python versions using pyenv, install the python build dependencies:
+```
+sudo apt-get update; sudo apt-get install make build-essential libssl-dev zlib1g-dev \
+libbz2-dev libreadline-dev libsqlite3-dev wget curl llvm \
+libncursesw5-dev xz-utils tk-dev libxml2-dev libxmlsec1-dev libffi-dev liblzma-dev
+```
+
+Basically, `pyenv` allows you to associate different python versions with different directories.
+
+* `pyenv install -l`: list pythons available to install
+* `pyenv install ...`: install a python
+* `pyenv versions`: list installed pythons
+* `pyenv shell ...`: use a python version in the current shell
+* `pyenv local ...`: set the python to use in this directory
+
+## Poetry
+
+Poetry is a package manager for python.
+It needs python to install, but once it is installed it will use whatever python is in your path (i.e., whatever you set with `pyenv`).
+
+```
+curl -sSL https://raw.githubusercontent.com/python-poetry/poetry/master/get-poetry.py | python
+```
+
+This added `export PATH="$HOME/.poetry/bin:$PATH"` to my `.zshrc`.
+You may need to follow the instructions to do something similar.
+
+It's also nice to
+
+```
+poetry config virtualenvs.in-project true
+```
+
+This puts the virtualenv configuration files in the directory you use poetry in, as opposed to a centralized location.
+The downside is you won't want to commit these files to your version control.
+
+
+## Putting it together
+An example of use
+
+Outside of any particular project, you'll need some versions of python for whatever work you need.
+```bash
+pyenv install 3.9.6
+```
+
+Then, to create a new project
+```bash
+mkdir test && cd test
+pyenv local 3.9.6 # when you cd into test, `python` will be python 3.9.6
+poetry init 
+poetry add numpy
+echo "import numpy\nimport sys\nprint(sys.version)\nprint(numpy.version.version)" > test.py
+poetry run python test.py
+```