Immutable manipulation of Python data structures, Clojure style

clojure, immutability, immutable, python
pip install pyclo==0.1.0



Pyclo is a collection of functions for Python named after the Clojure standard library to perform the equivalent operation of the respective Clojure function.

Install with

pip install pyclo


While immutability is neither idiomatic nor common in Python, it is still beneficial to implement the concept through engineering discipline. However, soon one will find oneself writing the same constructs over and over again, and even though these expressions are fairly succinct, it is much nicer to refer to them by name. The goal of this library is to provide a collection of functions that promote immutable manipulation of standard Python data structures as a concept without strictly enforcing it.

They say that there are only two hard problems in software engineering, one of them being naming. Clojure is chosen as a source of inspiration for these functions because the author of this library considers Clojure's naming the gold standard.


from pyclo import *
  • dissoc(dict, *keys) - return a shallow copy of dict without specified keys.
  • select_keys(dict, *keys) - return a shallow copy of dict only containing keys.
  • get_in(dict, keys, default=None) - look up a sequence of keys in a nested dict.


Pyclo's functions never modify their arguments. However, they don't create deep copies, either. This is a practical performance trade off and puts the library user in charge of mutation hygiene.


make test
make lint
make upload  # upload to Pypi