Rules¶

Warning: This is an experimental api. It is not a final design, and could be modified in the future.

Rules are a way to help prevent re-executing tasks unnecessarily. For example, not re-downloading a script if it has already been downloaded:

import os
import requests
from uranium import rule
from uranium.rules import WasChanged

@rule(WasChanged("./config.json"))
def main(build):
    with open(.path.join(build.root, "config.json"), "w+") as fh:
        resp = requests.get("http://myconfig.internalcompany.com")
        fh.write(resp.content)

Full API Reference¶

class uranium.rules.WasChanged(path)[source]¶

WasChanged is a rule that activates if the task has never run, or if a path has a file modified since the task last ran.

import subprocess
from uranium import rule
from uranium.rules import WasChanged

# only run tests if the code changed.
@rule(WasChanged("./my_module"))
def test(build):
    build.packages.install("pytest")
    return subprocess.call(["py.test", build.root])