examples: prepare for overriding sys.args

...which will be done in the next commit. One has to be careful with
sys.argv here because it uses different indexing than when passing args
explicitly.

Change-Id: I53833a5513abae0abd57065a49c0f357890e0820

gnpy/tools/cli_examples.py

@@ -12,7 +12,7 @@ from argparse import ArgumentParser
 from json import dumps
 import logging
 import os.path
-from sys import exit
+import sys
 from math import ceil
 from numpy import linspace, mean
 from pathlib import Path
@@ -46,24 +46,24 @@ def load_common_data(equipment_filename, topology_filename, simulation_filename=
             if next((node for node in network if isinstance(node, RamanFiber)), None) is not None:
                 print(f'{ansi_escapes.red}Invocation error:{ansi_escapes.reset} '
                       f'RamanFiber requires passing simulation params via --sim-params')
-                exit(1)
+                sys.exit(1)
         else:
             Simulation.set_params(sim_params)
     except exceptions.EquipmentConfigError as e:
         print(f'{ansi_escapes.red}Configuration error in the equipment library:{ansi_escapes.reset} {e}')
-        exit(1)
+        sys.exit(1)
     except exceptions.NetworkTopologyError as e:
         print(f'{ansi_escapes.red}Invalid network definition:{ansi_escapes.reset} {e}')
-        exit(1)
+        sys.exit(1)
     except exceptions.ConfigurationError as e:
         print(f'{ansi_escapes.red}Configuration error:{ansi_escapes.reset} {e}')
-        exit(1)
+        sys.exit(1)
     except exceptions.ParametersError as e:
         print(f'{ansi_escapes.red}Simulation parameters error:{ansi_escapes.reset} {e}')
-        exit(1)
+        sys.exit(1)
     except exceptions.ServiceError as e:
         print(f'{ansi_escapes.red}Service error:{ansi_escapes.reset} {e}')
-        exit(1)
+        sys.exit(1)
 
     return (equipment, network)
 
@@ -72,7 +72,7 @@ def _setup_logging(args):
     logging.basicConfig(level={2: logging.DEBUG, 1: logging.INFO, 0: logging.CRITICAL}.get(args.verbose, logging.DEBUG))
 
 
-def transmission_main_example():
+def transmission_main_example(args=None):
     parser = ArgumentParser()
     parser.add_argument('-e', '--equipment', type=Path,
                         default=_examples_dir / 'eqpt_config.json')
@@ -90,7 +90,7 @@ def transmission_main_example():
     parser.add_argument('source', nargs='?', help='source node')
     parser.add_argument('destination', nargs='?', help='destination node')
 
-    args = parser.parse_args()
+    args = parser.parse_args(args if args is not None else sys.argv[1:])
     _setup_logging(args)
 
     (equipment, network) = load_common_data(args.equipment, args.filename, args.sim_params, fuzzy_name_matching=args.names_matching)
@@ -101,14 +101,14 @@ def transmission_main_example():
     transceivers = {n.uid: n for n in network.nodes() if isinstance(n, Transceiver)}
 
     if not transceivers:
-        exit('Network has no transceivers!')
+        sys.exit('Network has no transceivers!')
     if len(transceivers) < 2:
-        exit('Network has only one transceiver!')
+        sys.exit('Network has only one transceiver!')
 
     if args.list_nodes:
         for uid in transceivers:
             print(uid)
-        exit()
+        sys.exit()
 
     # First try to find exact match if source/destination provided
     if args.source:
@@ -289,7 +289,7 @@ def _path_result_json(pathresult):
     return {'response': [n.json for n in pathresult]}
 
 
-def path_requests_run():
+def path_requests_run(args=None):
     parser = ArgumentParser(description='Compute performance for a list of services provided in a json file or an excel sheet.')
     parser.add_argument('network_filename', nargs='?', type=Path,
                         default=_examples_dir / 'meshTopologyExampleV2.xls',
@@ -306,7 +306,7 @@ def path_requests_run():
                         help='increases verbosity for each occurence')
     parser.add_argument('-o', '--output', type=Path)
 
-    args = parser.parse_args()
+    args = parser.parse_args(args if args is not None else sys.argv[1:])
     _setup_logging(args)
 
     _logger.info(f'Computing path requests {args.service_filename} into JSON format')
@@ -333,7 +333,7 @@ def path_requests_run():
         rqs = requests_from_json(data, equipment)
     except exceptions.ServiceError as e:
         print(f'{ansi_escapes.red}Service error:{ansi_escapes.reset} {e}')
-        exit(1)
+        sys.exit(1)
     # check that request ids are unique. Non unique ids, may
     # mess the computation: better to stop the computation
     all_ids = [r.request_id for r in rqs]
@@ -342,7 +342,7 @@ def path_requests_run():
             all_ids.remove(item)
         msg = f'Requests id {all_ids} are not unique'
         _logger.critical(msg)
-        exit()
+        sys.exit()
     rqs = correct_json_route_list(network, rqs)
 
     # pths = compute_path(network, equipment, rqs)
@@ -368,11 +368,10 @@ def path_requests_run():
         pths = compute_path_dsjctn(network, equipment, rqs, dsjn)
     except exceptions.DisjunctionError as this_e:
         print(f'{ansi_escapes.red}Disjunction error:{ansi_escapes.reset} {this_e}')
-        exit(1)
+        sys.exit(1)
 
     print(f'{ansi_escapes.blue}Propagating on selected path{ansi_escapes.reset}')
-    propagatedpths, reversed_pths, reversed_propagatedpths = compute_path_with_disjunction(
-        network, equipment, rqs, pths)
+    propagatedpths, reversed_pths, reversed_propagatedpths = compute_path_with_disjunction(network, equipment, rqs, pths)
     # Note that deepcopy used in compute_path_with_disjunction returns
     # a list of nodes which are not belonging to network (they are copies of the node objects).
     # so there can not be propagation on these nodes.