closive 0.0.0.dev26

Abstractions for callback-heavy control flows.

Closive

Data Transformatics for Python

Closive is a focussed toolkit that elevates a chain of ordinary Python call-backs into an explicit, inspectable, serialisable pipeline.
Each step is a plain callable; every intermediate value is wrapped in a Success or Failure from returns.result; and the entire chain is a first-class object that can be traced, visualised, re-combined, or persisted.

A pipeline is to callbacks what a module is to functions: a durable unit of composition, documentation, and reuse.

---

Table of Contents

1. Installation
2. Quick Start
3. Architecture & Core Abstractions
   3.1 Closure Pipeline
   3.2 Result Monad Integration
   3.3 Commutator
4. Introspection & Debugging
5. Error Handling Patterns
6. Collection Utilities
7. DataFrame & Plot Helpers
8. External Pipelines (YAML)
9. Extending Closive
10. Contributing
11. License

---

1 Installation

Closive is published on PyPI and supports Python 3.9 or later.

pip install closive

Optional extras for data-centric helpers:

pip install pandas numpy seaborn

---

2 Quick Start

from closive import closure, add, multiply, square

# 1. Construct a pipeline.
calc = (
    closure(lambda x: x + 1)   # seed
    >> multiply(3)             # step 1
    >> square                  # step 2
    >> add(5)                  # step 3
)

# 2. Execute like an ordinary function.
calc(2)
# → 50

# 3. Inspect the full run.
print(calc.explain(2))

Console output:

00 ✓ <lambda>      → 3
01 ✓ multiply(3)   → 9
02 ✓ square        → 81
03 ✓ add(5)        → 86

---

3 Architecture & Core Abstractions

3.1 Closure Pipeline

closure(fn=None, *, debug=False) → _Pipeline

• If fn is omitted the pipeline begins with the identity step.
• Append additional steps with the right-shift operator >>.
• The pipeline itself is callable; the first positional argument forms the initial value and any further *args/**kwargs are forwarded to every step in the chain.

pipeline = closure() >> square >> add(7)
result   = pipeline(4)          # → 23

3.2 Result Monad Integration

Internal execution is performed in terms of returns.result.Result:

• Success(value) represents normal flow.
• Failure(exc) represents an exception captured as data.

Closive automatically:

1. Wraps raw outputs into Success.
2. Short-circuits on the first Failure not otherwise handled.
3. Provides functional helpers (map, bind, alt, lash) for direct Result manipulation.

3.3 Commutator

A commutator is a pass-through helper that performs a side effect yet returns the input value unchanged.
Closive ships several ready-made instances.

from closive import tap, log, identity, noop

peek  = tap(print)    # send value to stdout
audit = log()         # log at INFO

A commutator is inserted exactly like any other step:

pipeline = closure() >> tap(lambda x: print("•", x)) >> square

Provided commutators:

Name	Purpose
identity	Return the value unchanged.
noop	Produce None irrespective of input.
tap(fn)	Execute fn(value), then forward.
log(...)	Log the value, then forward.
as_tuple	Return (x, x).
ignore_return	Synonym for identity.

---

4 Introspection & Debugging

Closive treats the pipeline as data and therefore supplies multiple inspection surfaces.

Method	Result & Notes
visualize()	ASCII diagram of the pipeline topology.
trace(value)	Generator of per-step event dictionaries.
explain(value, *, show_values=True)	Pretty, colourised, step-by-step report, also renders rich HTML in Jupyter.
inspect(value)	JSON-serialisable dict containing input, output, per-step success, and metadata.
get_step_result(value, index)	Execute up to index and return the intermediate result, raising on Failure.
_Pipeline(debug=True)	Immediate print of step names during execution.

---

5 Error Handling Patterns

Closive treats exceptions as values and lets you declare remediation strategies.

5.1 Static Fallback

safe = closure() >> divide(0) | 0    # ‘0’ returned on ZeroDivisionError

Operator | substitutes a static value and terminates the chain.

5.2 Dynamic Handler

def substitute(exc):
    return f"handled: {exc}"

recover = (
    closure()
    >> risky_op
    .handle_error(
        handler=substitute,
        continue_pipeline=True,       # execute remaining steps
        preserve_context=False        # ignore original exception afterwards
    )
)

handle_error parameters:

Name	Type	Meaning
fallback	Any	Static replacement value.
handler	Callable[[Exception], Any]	Dynamic replacement; takes precedence over fallback.
continue_pipeline	bool	If True, subsequent steps continue after replacement.
preserve_context	bool	If True, replacement value returned as (value, exc).
for_errors	Sequence[type[Exception]]	Only handle listed error types.
propagate_others	bool	Re-raise non-listed exceptions when for_errors is used.

---

6 Collection Utilities

The pipeline offers declarative operators that expect an iterable at runtime.

from closive import closure

stats = (
    closure()
    .map(lambda x: x ** 2)                   # element-wise
    .filter(lambda x: x % 2 == 0)            # keep even
    .fold(lambda acc, x: acc + x, 0)         # reduce to sum
)

stats([1, 2, 3, 4, 5])   # → 20

Additional structural helpers:

• repeat(n) – append the last step n additional times.
• drain() – remove the last step.

---

7 DataFrame & Plot Helpers

If pandas, numpy, and seaborn are present, Closive exposes helpers that turn numerical pipelines into tabular and graphical artefacts.

7.1 Linear Function & Plot

from closive import closure, linfunc, linplot

params = ([0, 1, 2, 3, 4], 2, 1)  # x-values, slope m, intercept b

p = closure(linfunc) >> linplot
plot = p(params)                  # seaborn.objects.Plot
plot.show()

7.2 Generic to DataFrame / Plot

from closive import closure, to_dataframe, to_plot

pipeline = closure() >> square >> to_dataframe >> to_plot
result, seaborn_plot, df = pipeline([0, 1, 2])

Return value is a triple so you can access whichever artefact you need.

---

8 External Pipelines (YAML Configuration)

Closive can materialise pipelines described in a YAML file at import time.

• Path: ~/.local/share/closive/pipelines.yml
• Each top-level key becomes an attribute on the imported closive module.
• The file is auto-generated with an illustrative example on first run.

Example entry:

square_plus_five:
  description: Square input then add five
  steps:
    - {module: closive.closures, function: square}
    - {module: closive.closures, function: add, args: [5]}

Programmatic helpers:

from closive import save_pipeline, reload_pipelines

save_pipeline("square_plus_five", pipeline, "Reusable default chain")
reload_pipelines()    # dynamically adds closive.square_plus_five

---

9 Extending Closive

9.1 Custom Result-Aware Step

from closive.closures import expects
from returns.result   import Success, Failure

@expects
def capped(max_value):
    def inner(result, *a, **k):
        return result.bind(
            lambda x: Success(x) if x <= max_value
            else Failure(ValueError(f"{x} exceeds {max_value}"))
        )
    inner.__name__ = f"capped({max_value})"
    return inner

Usage:

pipeline = closure() >> capped(10)

9.2 Augmenting _Pipeline

Because _Pipeline is an ordinary Python class, project-specific conveniences can be added dynamically.

def normalise(self):
    return self.map(lambda v: (v - min(v)) / (max(v) - min(v)))

from closive.closures import _Pipeline
_Pipeline.normalise = normalise

---

10 Contributing

Bug reports, feature proposals, and pull requests are welcome.

git clone https://github.com/kosmolebryce/closive
cd closive
pip install -r dev-requirements.txt
pytest

Contribution guidelines:

• Follow [Google Python Style Guide].
• Public APIs must include docstrings and unit tests.
• Commit messages should be imperative and scoped, e.g. “Add trace summariser”.

---

11 License

Closive is distributed under the MIT License.
See the LICENSE file for the full legal text.

---

© 2025 K. LeBryce. All rights reserved.