Python – Rob Allen's DevNotes

Cannot find zlib headers on macOS 10.15 Catalina

My new MacBook Pro 16" comes with Catalina and while setting up Python to develop rst2pdf, I discovered that Pillow wouldn't install.

    Running setup.py install for pillow ... error
    ERROR: Command errored out with exit status 1:

1 2	Running setup.py install for pillow ... error ERROR: Command errored out with exit status 1:

Looking through the long list of red text I came across:

    The headers or library files could not be found for zlib,
    a required dependency when compiling Pillow from source.

1 2	The headers or library files could not be found for zlib, a required dependency when compiling Pillow from source.

Aha! The way this was solved on the previous version of macOS (Mojave) was to use the macOS_SDK_headers_for_macOS_10.14.pkg installer to set up symlinks to header files from the old place to the new place. This doesn't work on Catalina, so… continue reading.

Posted on 27 November 2019 in Python, rst2pdf View all 9 comments

Creating virtual environments with Pyenv

rst2pdf is a Python 2 application that we're making compatible with Python 3. When developing Python applications, I've found it useful to be able to switch python versions easily and also set up clean environments to work in. To do this, I currently use pyenv. This is how I set it up: Install Pyenv On my Mac, I install pyenv & its sister project pyenv-virtualenv with Homebrew:

$ brew install readline xz
$ brew install pyenv pyenv-virtualenv

1 2	$ brew install readline xz $ brew install pyenv pyenv-virtualenv

You then need to add this to… continue reading.

Posted on 17 July 2019 in Python, rst2pdf View all 9 comments

Step debugging sphinx-build in PyCharm

I've been trying to solve an issue with the rst2pdf Sphinx extension which allows you to use rst2pdf to create a PDF of your Sphinx documentation rather than using Sphinx's default pdfTeX builder. In order to understand what was happening, I really wanted to inspect variable at certain stages of the process, which is easiest with a step debugger. As I already use PhpStorm for step debugging PHP, I fired up PyCharm and worked out… continue reading.

Posted on 26 June 2019 in Python, rst2pdf View all 2 comments

Category: Python

Cannot find zlib headers on macOS 10.15 Catalina

Creating virtual environments with Pyenv

Step debugging sphinx-build in PyCharm

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