Promise.resolve(value)

Converts values and foreign promises into Promises/A+ promises. If you pass it a value then it returns a Promise for that value. If you pass it something that is close to a promise (such as a jQuery attempt at a promise) it returns a Promise that takes on the state of value (rejected or fulfilled).

Promise.reject(value)

Returns a rejected promise with the given value.

Promise.all(list)

Returns a promise for a list. If it is called with a single argument then this returns a promise for a copy of that list with any promises replaced by their fulfilled values. e.g.

p = Promise.all([Promise.resolve('a'), 'b', Promise.resolve('c')]) \
       .then(lambda res: res == ['a', 'b', 'c'])

assert p.get() is True

Promise.cast(obj)

This function wraps the obj act as a Promise if possible. Python Futures are supported, with a callback to promise.done when resolved. Have the same effects as Promise.resolve(obj).

Promise.for_dict(d)

A special function that takes a dictionary of promises and turns them into a promise for a dictionary of values. In other words, this turns an dictionary of promises for values into a promise for a dictionary of values.

Promise.is_thenable(obj)

This function checks if the obj is a Promise, or could be promisifyed.

promise.catch(did_reject)

Sugar for promise.then(None, did_reject), to mirror catch in synchronous code.

promise.done(did_fulfill, did_reject)

The same semantics as .then except that it does not return a promise and any exceptions are re-thrown so that they can be logged (crashing the application in non-browser environments)