were writing in text-mode in PY3. and failing as encoding error.

Tokens work as usual while solving the DAG but
they are never assigned any values to/from the operation's functions.

+ TC included.
+ Docs updated.\+ Added `modifiers` superclass to facilitate identification code.
+ refactored FunctionalOperation._compute().

+ _norm_kwargs:
  + use isinstance() instead of type-equality checks,
    to support new modier classes;
    + avoid excessive dict searches with local vars.

not really needed, better be explicit which modifier is searched.

o
+ Closes yahoo#17

receiving partial inputs, needed for other operations.

+ The x2 TCs added just before are now passing.

NOTE dict are not deterministic in <PY3.6.
So this commit would not improve determinism
in those pythons.

+ build: add `boltons` dependency for ndexedSet.
+ doc: mark all set usage if affect determinism.
+ e.g. see reproducibility problem in yahoo#14.

…uts asked

needed to refactor the new pruning algorithm.

- expected 2 TCs fail for yet-to-be-solved yahoo#24 & yahoo#25 bugs.

the later described in yahoo#21.

override intermediate data.

More changes only for newer pruning TCs:
+ refact(test): rename graph-->netop vars for results of compose(),
  to avoid of `graph.net.graph`.
+ Explain failure modes in v1.2.4 & this merged branch (yahoo#19 + yahoo#23).

not after compose().

+ All TCs pass ok.
+ NOTE this is not yet what is described in yahoo#21.

to pass +TC checking DeleteInst vary when inputs change.

- x4 TCs still failing, and need revamp of dag-solution.

+ Read the next doc-only commit to understand changes.
+ Renamed:
  + net.steps --> net.execution_plan.
  + (old)compile() --> _build_execution_plan()
  + _find_necessary_steps() --> (new)compile() + _solve_dag()
    compile() became the master function invoking _solve_dag &
    _build-execution_plan(), and do the caching.
+ refact(compute()): extract common tasks from sequential/parallel.
+ refact show_layers() to allow full-print, geting also string
  (not just printing), and using custom classes for representation.
+ Raise AssertionError when invalid class in plan.
  it's a logic error, not a language type-error.

Probaly unreported bug in v1.2.4 for '_neccessary_steps_cache`.

+ Pruning behaves correctly also when outputs given;
  this happens by breaking incoming provide-links
  to any given intermedediate inputs.
+ Unsatisfied detection now includes those without outputs
  due to broken links (above).
+ Remove some uneeded "glue" from unsatisfied-detection code,
  leftover from previous compile() refactoring.
+ Renamed satisfiable --> satisfied.
+ Improved unknown output requested raise-message.
+ x3 TCs PASS, x1 in yahoo#24 and the first x2 in yahoo#25.
- 1x TCs in yahoo#25 still FAIL, and need "Pinning" of given-inputs
  (the operation MUST and MUST NOT run in these cases).

numpy was used just for its assert_raise

…must run

- WIP: PARALLEL execution not adding PINS!
+ Insert "PinInstructions" in the execution-plan to avoid overwritting.
+ Add `_overwrite_collector` in `compose()` to collect re-calculated values.
+ FIX the last TC in yahoo#25.

- STILL buggy PIN on PARALLEL, 2 DISABLED TCs FAIL:
  - test_pruning_with_given_intermediate_and_asked_out()
  - test_unsatisfied_operations_same_out()
+ move check if value in asked outputs before cache-evicting it
  in build-execution-plan time - compute methods
  don't need outputs anymore.
+ test: speed up parallel/multihtread TCs
  by reducing delays & repetitions.
+ refact: network rightfully adopted stray functions
  for parallel processing - they all worke on the net.graph,
+ upd: networkx api by indexing on `dag.nodes` views.
+ enh: add log message when deleting in parallel
  (in par with sequential code).
+ refact: var-renames, if-then-else simplifications, pythonisms.
+ doc: A lot!

thanks to @andres-fr.

- WIP: x4 TCs FAIL and still not discovered th bug :-(
+ BUT ALL+AUGMENTED PARALLEL TCs pass
  (yahoo#26 were failing some)
+ refact: net stores also `pruned_dag` (not only `steps`).
+ refact: _solve_dag() --> _prune_dag().
+ doc: +a lot.
+ TODO: store pruned_dag in own ExePlan class.

- SAME x4 TCs FAIL like parent.
+ refact: revive net.steps --> net.last_plan
+ BREAK: inverse the order of outputs/inputs args in net.compute()
+ refact: use iset() to merge.

to use it also on stary DAGs.  Keep delegation.

(see yahoo#13 for an example):

+ test all chained plot() methods from netop.

+ enh TC with parallel.
+ Scavenged from yahoo#20.

+ retorfitted to try all available formats.
+ list of forbidden formats based on my failres

+ doc: rename in sample code: netop --> pipeline.
+ enh(build): add `ipython` in test dependencies.
+ include it in the plot TC.

...pytest has problems with 3.4.

to avoid copying plot() doc+sig around

- still x4 TCs fail...

to bring back PlotMixin to change together stuff.

+ enh(plan): also sequential execution collects accounts executed.
+ refact(plan): executed_nodes-->executed.

... based on Law of Demeter simplify kwargs,
defined in one place.

+ enh: plotters "suggest" kwargs, possinly to override them
  (no duplcate arg when attempted).

+ FIX: apply thickness as in legend also for operators.
+ enh: don't cluster if no nodes pruned.
+ enh: netop includes its name a graph-title.
+ color palette: wheat filled nodes.
+ reuse common func.

... bugged in the opening commit d403783 of this PR, and
discovered 68(!) commits later, and all that time had to live
with x4 broken TCs with asked-outputs.

+ ENH: strongly refatctored TC to detect nulls & dupes.

+ Partial fix deterministic results (yahoo#22-2.4.3i).

+ test: some refacts on vars & for the uploaded images.
+ MARK SPURIOUS FAILS in < PY3.6 due to unordered dicts
  eg https://travis-ci.org/ankostis/graphkit/jobs/594813119

to support _repr_svg(), and it works without any flag.

+ graphop label renames,
+ DOT shortening.

+ FIX: `graph` is a DOT keyword, eg  pydot/pydot#111
  + Replaced `graph` --> `graphop`, inline with future refactoring.
+ Refactored example code.
+ New "Plotting" section under Quickstart.
+ Copy README instructions to main docs.
+ Abandoned `example_graph.svg`, replaced with `intro.svg`.
+ Recommend `.png` --> `.svg`, to save storage space.
- discovered BUG in MERGE saumple code (empty!).

... to adopt pytest args
+ mark wheel a universal.

got values from v1.2.4
- ALL MERGE TCs FAIL!

many commits ago.

Never got it bc TC were not checking merges!

needed to give the sidefeect as input.