Change _libwarpx.py functions to LibWarpX class methods (#2696)

* Initial attempt at moving function into LibWarpX

* Bugfix - undefined structs in get_particle_theta

This is untested, identified by IDE/visual inspection only

* Unify newlines

* Delete libwarpx.clight (duplicated picmi.py)

See picmi.constants.c

* Change function descriptive comment to docstring

Also remove extra newline in __init__ beginning.

* Replace pywarpx/_libwarpx calls appropriately

* Fix atexit register of finalize function

* Reorder WarpX.py imports for pre-commit

* Use picmi.Simulation.extension = libwarpx alias

This will hopefully preempt user script changes if we restructure things
to allow multiple WarpX runs to be done within a single Python script.

* Fix libwarpx ref in WarpX.getProbLo/getProbHi

* Update get_particle_boundary_buffer doc reference

1 files changed, 7 insertions, 8 deletions

diff --git a/Examples/Tests/restart/PICMI_inputs_runtime_component_analyze.py b/Examples/Tests/restart/PICMI_inputs_runtime_component_analyze.py
index ffb820fed..1fa8862f0 100755
--- a/Examples/Tests/restart/PICMI_inputs_runtime_component_analyze.py
+++ b/Examples/Tests/restart/PICMI_inputs_runtime_component_analyze.py
@@ -7,7 +7,6 @@
 import sys
 
 import numpy as np
-import pywarpx
 from pywarpx import callbacks, picmi
 
 ##########################
@@ -113,7 +112,7 @@ sim.initialize_warpx()
 ##########################
 
 
-pywarpx.add_real_comp('electrons', 'newPid')
+sim.extension.add_real_comp('electrons', 'newPid')
 
 def add_particles():
 
@@ -127,7 +126,7 @@ def add_particles():
     w = np.ones(nps) * 2.0
     newPid = 5.0
 
-    pywarpx.add_particles(
+    sim.extension.add_particles(
         species_name='electrons', x=x, y=y, z=z, ux=ux, uy=uy, uz=uz,
         w=w, newPid=newPid
     )
@@ -138,18 +137,18 @@ callbacks.installbeforestep(add_particles)
 # simulation run
 ##########################
 
-step_number = pywarpx.getistep(0)
+step_number = sim.extension.getistep(0)
 sim.step(max_steps - 1 - step_number)
 
 ##########################
 # check that the new PIDs are properly set
 ##########################
 
-assert(pywarpx.get_particle_count('electrons') == 90)
-assert (pywarpx.get_particle_comp_index('electrons', 'w') == 0)
-assert (pywarpx.get_particle_comp_index('electrons', 'newPid') == 4)
+assert(sim.extension.get_particle_count('electrons') == 90)
+assert (sim.extension.get_particle_comp_index('electrons', 'w') == 0)
+assert (sim.extension.get_particle_comp_index('electrons', 'newPid') == 4)
 
-new_pid_vals = pywarpx.get_particle_arrays(
+new_pid_vals = sim.extension.get_particle_arrays(
     'electrons', 'newPid', 0
 )
 for vals in new_pid_vals: