Voodoo 1.6.0

Template system for project skeletons

Voodoo is a template system for project skeletons (similar to the template part of PasteScript):

• It can make a copy of a project skeleton processing some files, filter others, etc.

• Works with local paths and git/hg URLs.

• It generates a beautiful output and take care of not overwrite existing files, unless instructed to do so.

• BSD License. See LICENSE for more details.

Above, Voodoo sample output as used in a program

Requirements:

• Pypy or Python 2.7, 3.3 or newer.

• It also uses the Jinja2 and Colorama Python libraries.

As a command line tool

Install it by doing:

$  pip install voodoo

Available commands:

voodoo new <template> <dest>

Render the project template at the destination directory. The template can be a:

• Git URL (eg: [e-mail]:jpscaletti/voodoo-demo.git),

• Path to a local folder, or

• The name of a previously downloaded template with voodoo install …

voodoo install <URL>

Download the template in the folder specified by the VOODOO_TEMPLATES_DIR environment variable (by default is ~/.voodoo/templates/)

voodoo list

List all the downloaded templates.

Examples:

$  voodoo new [e-mail]:jpscaletti/voodoo-demo.git mydemo

or

$ voodoo install [e-mail]:jpscaletti/voodoo-demo.git $ voodoo new voodoo-demo anotherdemo

In your programs

First of all install it and/or add it to your requirements.txt:

$  pip install voodoo

The API is very simple. A render_skeleton function that takes two absolute paths: the project skeleton to process, and where to copy it.:

from voodoo import render_skeleton

render_skeleton(skeleton_path, new_project_path)

It also provides some prompt functions that take user input, to help you to make interactive scripts. See the ‘API’ section of this README for more information.

How it works

The content of the files inside the skeleton are copied to the destination without changes, unless are suffixed with the extension ‘.tmpl’. In that case, the templating engine will be used to render them.

A slightly customized Jinja2 templating is used. The main difference is that variables are referenced with [[ name ]] instead of {{ name }} and blocks are [% if name %] instead of {% if name %}. To read more about templating see the Jinja2 documentation.

Use the data argument to pass whatever context you want to be available in the templates. The arguments can be any valid Python value, even a function:

from hashlib import sha256
from os import urandom
from voodoo import render_skeleton

data = {
    'package': 'demo',
    'py3': True,
    'make_secret': lambda: sha256(urandom(48)).hexdigest()
}
render_skeleton(skeleton_path, new_project_path, data=data)

so in your template you can have:

import [[ package ]]

secret = '[[ make_secret() ]]'
[% if py3 %]
msg = 'Python 3!'
[% else %]
msg = 'meh'
[% endif %]

Your folders and files can also use the [[ name ]] notation: mytemplate/[[ foo ]]/something/[[ bar ]].txt

Using it in a script

It’s easy to integrate Voodoo with your own scripts. The following example it’s a classic make new project script found in many popular frameworks:

from os.path import join, dirname, basename
from voodoo import render_skeleton


default_context = {
    'foo': 'bar',
}
SKELETON_PATH = join(dirname(__file__), '..', 'tests', 'demo')


def new_project(path, options):
       data = default_context.copy()
    data['project_name'] = basename(path)
    render_skeleton(SKELETON_PATH, path, data=data, **options)


if __name__ == '__main__':
       import argparse

    parser = argparse.ArgumentParser(description='Create a new project')
    parser.add_argument('path', help='The name or fullpath of the new project')
    parser.add_argument('-p', '--pretend', action='store_true',
                        help='Run but do not make any changes')
    parser.add_argument('-f', '--force', action='store_true',
                        help='Overwrite files that already exist, without asking')
    parser.add_argument('-s', '--skip', action='store_true',
                        help='Skip files that already exist, without asking')
    parser.add_argument('-q', '--quiet', action='store_true',
                        help='Suppress status output')

    args = parser.parse_args()
    da = vars(args)
    new_project(da.pop('path'), da)

You can se this example working in the examples folder. Play with it, generate a new project and manually update some files. Then run the script again to see how it detects what files has changed, and what files are identical and with no need of regeneration.

An interactive version of this script could be made using the voodoo.prompt and/or the voodoo.prompt_bool helper functions.

VCS Support

Voodoo supports rendering project skeletons from a version control system repository. Git and Mercurial are supported. It requires a working VCS command on your path: git or hg.

The forms of the URL is the same that the pip installer uses, detecting the type of VCS using URL prefixes: “git+” or “hg+”.

Git

Currently supports cloning over git, git+https and git+ssh:

git+git://git.myproject.org/MyProject
git+https://git.myproject.org/MyProject
git+ssh://git.myproject.org/MyProject
[e-mail]:MyProject

Passing branch names, a commit hash or a tag name is possible like so:

git://git.myproject.org/MyProject.git@master
git://git.myproject.org/MyProject.git@v1.0
git://git.myproject.org/MyProject.git@da39a3ee5e6b4b0d3255bfef95601890afd80709

Mercurial

The supported schemes are: hg+http, hg+https, hg+static-http and hg+ssh:

hg+http://hg.myproject.org/MyProject
hg+https://hg.myproject.org/MyProject
hg+ssh://hg.myproject.org/MyProject

You can also specify a revision number, a revision hash, a tag name or a local branch name like so:

hg+http://hg.myproject.org/MyProject@da39a3ee5e6b
hg+http://hg.myproject.org/MyProject@2019
hg+http://hg.myproject.org/MyProject@v1.0
hg+http://hg.myproject.org/MyProject@special_feature

API

render_skeleton

render_skeleton (src_path, dst_path, data=None, filter_ext=None, pretend=False, force=False, skip=False, quiet=False, envops=None)

src_path:

Absolute path to the project skeleton

dst_path:

Absolute path to where to render the skeleton

data:

Data to be passed to the templates, as context.

filter_this:

A list of names or shell-style patterns matching files or folders that musn’t be copied. The default is: ['.*', '~*', '*.py[co]']

include_this:

A list of names or shell-style patterns matching files or folders that must be included, even if its name are in the filter_this list. Eg: ['.gitignore']. The default is an empty list.

pretend:

Run but do not make any changes

force:

Overwrite files that already exist, without asking

skip:

Skip files that already exist, without asking

quiet:

Suppress the status output

envops:

Extra options for the Jinja template environment.

prompt

prompt (text, default=None, validator=None)

Ask a question via raw_input() and return their answer.

text:

prompt text

default:

default value if no answer is provided.

validator:

Optional. A function that will validate the provided value. If the validator raises a ValueError, the error message is printed and the user prompted for another value. The return value from the validator is returned from prompt, allowing a validator to change the value as required.

prompt_bool

prompt_bool (text, default=False, yes_choices=None, no_choices=None)

Ask a yes/no question via raw_input() and return their answer.

text:

prompt text

default:

default value if no answer is provided.

yes_choices:

default ['y', 'yes', '1', 'on', 'true', 't']

no_choices:

default ['n', 'no', '0', 'off', 'false', 'f']

prompt_int

prompt_int (text, default=None, min_value=None, max_value=None)

text:

prompt text

default:

default value if no answer is provided. Optional.

min_value:

Optional. Numbers below this are rejected

max_value:

Optional. Numbers above this are rejected

@as_validated_prompt

voodoo.cli.as_validated_prompt (validator)

Used as a decorator. Makes a new prompt function from a validator. For example, to make a prompt that casts its input to a float you could write:

@as_validated_prompt
def prompt_float(value):
    return float(value)


my_float = prompt_float('Enter a number', default=3.14)

---

copyright:

Juan-Pablo Scaletti.

license:

BSD, see LICENSE for more details.