Mas alla de las guias de estilo | Talk 22 May , 2019

adapter_example.py

"""
Pythonic means "coding beautifully in harmony with the language to get the
maximum benefits from python"

Learn to recognize non-pythonic APIs and to recognize good code.
Dont get distracted by PEP8. Focus first on Pythonic vs NonPythonic(P vs NP)

When needed, write an adapter class to convert from the former to the latter
==========================================================
"""
# Adapter Pattern Class

import jnettool.tools.elements.NetworkElement
import jnettool.tools.Routing


class NetworkElementError(Exception):
    pass


class NetworkElement:
    def __init__(self, ipaddr):
        self.ipaddr = ipaddr
        self.oldne = jnettool.tools.elements.NetworkElement(ipaddr)

    @property
    def routing_table(self):
        try:
            return RoutingTable(self.oldne.getRoutingTable())
        except jnettool.tools.elements.MissingVar:
            raise NetworkElementError("No routing table")

    def __enter__(self):
        return self

    def __exit__(self, exctype, excinst, exctb):
        if exctype == NetworkElementError:
            logging.exception("No routing table form")
            self.oldne.cleanup("rollback")
        else:
            self.oldne.cleanup("commit")

        return self.oldne.disconnect()


class RoutingTable:
    def __init__(self, oldrt):
        self.oldrt = oldrt

    def __len__(self):
        return self.oldrt.getSize()

    def __getitem__(self, index):
        if index >= len(self):
            raise IndexError
        return Route(self.oldrt.getRouteByIndex(index))


class Route:
    def __init__(self, old_route):
        self.old_route = old_route

    @property
    def name(self):
        return self.old_route.getName()

    @property
    def ipaddr(self):
        return self.old_route.getIPAddr()

implementation.py

from nettools import NetworkElement

with NetworkElement("171.0.2.45") as ne:
    for route in ne.routing_table:
        print ("%15s -> %s" % (route.name, route.ipaddr))

review_code.py

import jnettool.tools.elements.NetworkElement, \
       jnettool.tools.Routing, \
       jnettool.tools.RouteInspector


ne=jnettool.tools.elements.NetworkElement( "171.0.2.45" )

try:
    routing_table=ne.getRoutingTable() # fetch table

except jnettool.tools.elements.MissingVar:
    # Record table fault
  logging.exception( ''' No routing table found''' )
  ne.cleanup( ''' rollback ''' )

else:
    num_routes=routing_table.getSize() # determinate table size
    for RToffset in range( num_routes ):
            route=routing_table.getRouteByIndex( RToffset )
            name=route.getName()                   # route name
            ipaddr=route.getIPAddr()               # ip address
            print( "%15s -> %s" % (name, ipaddr) ) # Format nicely

finally:
    ne.cleanup( ''' commit ''' ) # lockin changes
    ne.disconnect()

El codigo fue tomado de este video https://www.youtube.com/watch?v=wf-BqAjZb8M&t=2137s
PDF de la presentacion https://www.dropbox.com/s/f4du53jqxkf1e9v/Beyong_style_guides.pdf?dl=0