Using Copier Answers to rerun templates quickly

The copier answers file is a key component to making your templates re-runnable. Let's look at the example for my setup.py.

❯ tree ~/.copier-templates/setup.py
/home/walkers/.copier-templates/setup.py
├── [[ _copier_conf.answers_file ]].tmpl
├── copier.yml
├── setup.cfg
└── setup.py.tmpl

0 directories, 4 files

Inside of my [[ _copier_conf.answers_file ]].tmpl file is this, a message not to muck around with it, and the answers in yaml form. The first line is just a helper for the blog post.

# ~/.copier-templates/setup.py/\[\[\ _copier_conf.answers_file\ \]\].tmpl
# Changes here will be overwritten by Copier; NEVER EDIT MANUALLY
[[_copier_answers|to_nice_yaml]]

Inside my copier.yml I have setup my _answers_file to point to a special file. This is because this is not a whole project template, but one just for a single file.

# copier.yml
# ...
_answers_file: .setup-py-copier-answers.yml

Once I change the _answers_file I was incredibly stuck

Run it

I'm making a library of personal copier templates in my
~/.copier-templates directory and I am going to run it from there.

copier copy ~/.copier-templates/setup.py

Results

After rendering the template we have the following content in our .setup.setup-py-copier-answers.yml file. This will allow us to update quick if we ever change our template.

# .setup-py-copier-answers.yml
# Changes here will be overwritten by Copier; NEVER EDIT MANUALLY
_src_path: /home/walkers/.copier-templates/setup.py
author_github: waylonwalker 
author_name: Waylon Walker 
description: awesomeness 
framework: null 
keywords: null 
package_name: my-package

Update it

This is where I was most stuck, primarily becuase -a <answers_file> must come exactly after the base command copier. This felt a bit odd to and not where I expected it so it.

copier -a .setup-py-copier-answers.yml update

Stop asking all these damn questions

So the defaults are now changed to our previous results, but it keeps asking for them. To stop asking we can simply add a -f flag.

copier -fa .setup-py-copier-answers.yml update