pathaliases

A python package for handling path aliases.

Path aliases can be loaded directly from YAML files:

dir/:
  subdir/:
    alias: SUBDIR
    some/other/dir/:
      alias: SUBDIR_2

file.txt: { alias: [FILE, ALTERNATE_ALIAS] }

dir2/:
  extra_keys: are ignored
  alias: 2ndDir

some/very/long/path/:
  into/a/deep/file/hierarchy/:
    can/be/addressed/with: { alias: A_PATH_INDEPENDANT_ALIAS }

Resolving this with pathaliases.resolve_yaml_to_path_strings("aliases.yml") returns a dictionary:

{
    "SUBDIR": "dir/subdir/",
    "SUBDIR_2": "dir/subdir/some/other/dir/"
    "FILE": "file.txt",
    "ALTERNATE_ALIAS": "file.txt",
    "2ndDir": "dir2/",
    "A_PATH_INDEPENDENT_ALIAS": "some/very/long/path/into/a/deep/file/hierarchy/can/be/addressed/with"
}

Which can be used to make codebases independent from paths:

# Before
subdir = "dir/subdir/"
subdir_2 = os.path.join(subdir, subdir_2)

# After: *where* the dirs are is configurable
aliases = pathaliases.resolve_yaml_to_path_strings("aliases.yml")
subdir = aliases["SUBDIR"]
subdir_2 = aliases["SUBDIR_2"]

pathaliases is designed to be:

• Simple - It just concatenates all the keys that lead up to an alias.
• Readable - Developers and admins should be able to edit paths easily.
• Standard - It uses standard file formats and conventions, making it easy to port to other languages.

Installation

Clone the repo:

$ git clone https://github.com/adamkewley/pathaliases.git
$ python setup.py install

Usage

Resolve aliases directly from a YAML file:

import pathaliases

aliases = pathaliases.resolve_yaml_to_path_strings("aliases.yml")

print(aliases["SUBDIR"])  # echoes: "dir/subdir/"

Resolve aliases from a dict:

import pathaliases

aliases_dict = {
    "dir/": {
        "subdir/": {"alias": "SUBDIR"}
    }
}

aliases = pathaliases.resolve_path_strings(aliases_dict)
print(aliases["SUBDIR"])  # echoes: "dir/subdir/"

Substituting Variables

Alias files can also contain variables, templated with ${VARNAME}:

foo/:
  ${var}/:
    alias: ${key}

pathaliases allows you to pass in an environment when evaluating paths:

env = {
  "var": "bar",
  "key": "some_alias"
}

aliases =  pathaliases.resolve_yaml_to_path_strings("aliases.yml", env=env)

aliases == {
  "some_alias": "foo/bar/",
}