Installation

pip install manipulator

Usage

manipulator mainly exposes three functions, get, update, and set. get retrieves data, update transforms it based on its form, and set transforms it by simply resetting. Transformations can be applied in place or on a copy. The default is in place, because copying is expensive. If you want a copy of the data, set the keyword argument in_place to True.

It uses a query “language” not unlike CSS, albeit much, much simpler. The only two entities in this “language” are IDs—denoted by #—and Classes—denoted by .. IDs are unique, whereas Classes are collections of all leaf values that conform.

A few motivating examples (a more exhaustive list can be found in the test directory):

import manipulator

manipulator.get({"k": [1, [2], 3]}, "#k #1 #0")
# => 2 (note how list indices are coerced into integers)

manipulator.get([{"k": "v"}, {"k": "v2", "k2": "v3"}], ".k")
# => ["v", "v2"]

manipulator.get([{"k": "v"},
                 {"k": {
                    "a": [{"k": 10}, {"k": 11}]
                  }
                 }], ".k #1 #a .k")
# => [10, 11]

manipulator.set({"k": [1, [2], 3]}, "#k #1 #0", 3)
# => {"k": [1, [3], 3]} (in place)

manipulator.set({"k": [1, [2], 3]}, "#k #1 #0", 3, in_place=False)
# => {"k": [1, [3], 3]} (will create a copy of the data)

manipulator.set([{"k": "v"},
                 {
                   "k": {
                     "a": [{"k": 10}, {"k": 11}]
                    }
                 }], ".k #1 #a .k", 100)
# => [{"k": "v"}, {"k": {"a": [{"k": 100}, {"k": 100}]}}]

manipulator.update({"k": [1, [2], 3]}, "#k #1 #0", lambda x: x-1)
# => {"k": [1, [1], 3]} (in place, use in_place=False to copy)

manipulator.update([{"k": "v"},
                    {
                      "k": {
                        "a": [{"k": 10}, {"k": 11}]
                      }
                    }], ".k #1 #a .k", lambda x: x+1)
# => [{"k": "v"}, {"k": {"a": [{"k": 11}, {"k": 12}]}}]

That is all.

Have fun!