Using Pre/Post-Generate Hooks

New in cookiecutter 0.7

You can have Python or Shell scripts that run before and/or after your project is generated.

Put them in hooks/ like this:

├── {{cookiecutter.project_slug}}/
├── hooks
│   ├──
│   └──
└── cookiecutter.json

Shell scripts work similarly:

├── {{cookiecutter.project_slug}}/
├── hooks
│   ├──
│   └──
└── cookiecutter.json

It shouldn’t be too hard to extend Cookiecutter to work with other types of scripts too. Pull requests are welcome.

For portability, you should use Python scripts (with extension .py) for your hooks, as these can be run on any platform. However, if you intend for your template to only be run on a single platform, a shell script (or .bat file on Windows) can be a quicker alternative.

Writing hooks

Here are some details on how to write pre/post-generate hook scripts.

Exit with an appropriate status

Make sure your hook scripts work in a robust manner. If a hook script fails (that is, if it finishes with a nonzero exit status), the project generation will stop and the generated directory will be cleaned up.

Current working directory

When the hook scripts script are run, their current working directory is the root of the generated project. This makes it easy for a post-generate hook to find generated files using relative paths.

Template variables are rendered in the script

Just like your project template, Cookiecutter also renders Jinja template syntax in your scripts. This lets you incorporate Jinja template variables in your scripts. For example, this line of Python sets module_name to the value of the cookiecutter.module_name template variable:

module_name = '{{ cookiecutter.module_name }}'

Example: Validating template variables

Here is an example of a pre-generate hook script, defined at hooks/, that validates a template variable before generating the project:

import re
import sys

MODULE_REGEX = r'^[_a-zA-Z][_a-zA-Z0-9]+$'

module_name = '{{ cookiecutter.module_name }}'

if not re.match(MODULE_REGEX, module_name):
    print('ERROR: %s is not a valid Python module name!' % module_name)

    # exits with status 1 to indicate failure

Example: Conditional files / directories

Here is an example of a post-generate hook script. The file hooks/ shows how to achieve conditional control of files and directories after generating the project.

The script ensures that the directory structure is as expected by removing unwanted files and directories:

import os

    '{% if cookiecutter.packaging != "pip" %} requirements.txt {% endif %}',
    '{% if cookiecutter.packaging != "poetry" %} poetry.lock {% endif %}',

for path in REMOVE_PATHS:
    path = path.strip()
    if path and os.path.exists(path):
        if os.path.isdir(path):