Updating from Previous Versions#

When updating a project generated with the same major version of PyScaffold [1], running putup --update should be enough to get you going. However updating from previous major versions of PyScaffold will probably require some manual adjustments. The following sections describe how to update from one major version into the following one.


Before updating make sure to commit all the pending changes in your repository. If something does not work exactly how you expected after the update, please revise the changes using a diff and perform the necessary corrections.

Updates from PyScaffold 2 to PyScaffold 3#

Since the overall structure of a project set up with PyScaffold 2 differs quite much from a project generated with PyScaffold 3 it is not possible to just use the --update parameter. Still with some manual efforts an update from a scaffold generated with PyScaffold 2 to PyScaffold 3’s scaffold is quite easy. Assume the name of our project is old_project with a package called old_package and no namespaces then just:

  1. make sure your worktree is not dirty, i.e. commit all your changes,

  2. run putup old_project --force --no-skeleton -p old_package to generate the new structure inplace and cd into your project,

  3. move with git mv old_package/* src/old_package/ --force your old package over to the new src directory,

  4. check git status and add untracked files from the new structure,

  5. use git difftool to check all overwritten files, especially setup.cfg, and transfer custom configurations from the old structure to the new,

  6. check if python setup.py test sdist works and commit your changes.

Updates from PyScaffold 3 to PyScaffold 4#

Most of the time, updating from PyScaffold 3 should be completely automatic. However, since in version 4 we have adopted Python’s new standards for packaging (PEP 517/PEP 518), you might find the new build process incompatible.

If that is the case, you might want to try reverting to the legacy behaviour and preventing the build tools from using isolated builds (PEP 517). That can be easily done by deleting the pyproject.toml file from your package root.

You will need, though, to manually follow a few extra steps to make sure everything works:

  1. Remove PyScaffold from your build dependencies (setup_requires in setup.cfg) and add setuptools-scm.


    The use of setup_requires is discouraged. When updating to v4 PyScaffold will remove this field automatically and transfer the dependencies to the pyproject.toml :: build-system.requires field, which means you may need to manually place them back when deleting pyproject.toml. Alternatively you can ditch setup_requires completely and rely on other tools like tox or make to build your project with the correct dependencies in place inside a virtual environment. This have the advantage of increasing reproducibility. With tox you can specify a build testenv with the skip_install option and the required build time dependencies listed in deps.

  2. Migrate any configuration options for tools that might be using pyproject.toml to alternative files. For example if you have isort and coverage configurations in your pyproject.toml, you might want to rewrite them in the .isort.cfg and .coveragerc files respectively.

  3. Please open an issue with PyScaffold so we understand with kind of backward incompatibilities PEP 517 and PEP 518 might be causing and try to help. Similarly you might also consider opening an issue with setuptools.


For the time being you can use the transitional --no-pyproject option, when running putup, but have in mind that this option will be removed in future versions of PyScaffold.

PyScaffold 4 also adopts the PEP 420 scheme for implicit namespaces and will automatically migrate existing packages. This is incompatible with the previously adopted pkg_resources methodology. Fortunately, this will not affect you if you are not using namespaces, but in the case you are, installing a new PEP 420-compliant package in an environment that already contains other packages with the same namespace but that use the pkg_resources methodology, will likely result in errors (please check the official packaging namespace packages guides for more information).

To solve this problem you will need to either migrate the existing packages to PEP 420 or revert some specific configurations in setup.cfg after the update. In particular packages = find_namespace: should be converted back to packages = find: in the [options] section (use a git difftool to help you with that). If using Sphinx for the documentation, you can also remove the --implicit-namespaces option in the cmd_line_template variable in the docs/conf.py file.


Existing regular Python files (or other directories containing Python files) that do not belong to the package distribution but are placed inside the src folder (such as example files not meant to be packaged), can cause problems when building your package.

Please move these files if necessary to their own separated folders (e.g. the docs folder or a new examples folder in the root of the repository), or revert back to the pkg_resources implementation. Just have in mind that PyScaffold, considers the src directory to be exclusively dedicated to store files meant to be distributed, and will rely on that assumption on its future versions and updates.