Maybe something like the following. Give you a sorted CSV for post processing.
# -*- coding: utf-8 -*-
'''
Written for PSSE v33.4 and Python 2.7.0.
For showing system loading.
'''
import psspy
import os, operator, csv
__version__ = '1.0.0'
__date__ = '2019.08.13'
def showLoading(int_sid, int_tie, int_flag, str_rate_opt='PCTMVA', int_round=4, str_path_csv_out=''):
'''
This function finds the loading of the branches and optionally output the findinding as a CSV.
Parameters
----------
int_sid : int
The subsystem ID.
int_tie : int
Tie line option.
int_flag : int
Subsystem branch option.
str_rate_opt : str
Branch flow optional string.
Default = 'PCTMVA', i.e., percent MVA loading of Rating A.
int_round : int
Percentage rounding option.
Default = 4, i.e., round to the 4th decimal number.
str_path_csv_out : str
Optional. The output CSV file full path.
If an empty string is given, the findings will be printed to the console.
Default = empty string.
Returns
-------
None.
Reference
----------------------
PSSE API manual.
'''
# on exception, through exception and stop the script
psspy.throwPsseExceptions = True
_, list_from_bus_names = psspy.abrnchar(sid=int_sid, ties=int_tie, flag=int_flag, string='FROMEXNAME')
list_from_bus_names = list_from_bus_names[0]
_, list_from_bus_no = psspy.abrnint(sid=int_sid, ties=int_tie, flag=int_flag, string='FROMNUMBER')
list_from_bus_no = list_from_bus_no[0]
_, list_to_bus_names = psspy.abrnchar(sid=int_sid, ties=int_tie, flag=int_flag, string='TOEXNAME')
list_to_bus_names = list_to_bus_names[0]
_, list_to_bus_no = psspy.abrnint(sid=int_sid, ties=int_tie, flag=int_flag, string='TONUMBER')
list_to_bus_no = list_to_bus_no[0]
_, list_brn_id = psspy.abrnchar(sid=int_sid, tie=int_tie, flag=int_flag, string='ID')
list_brn_id = list_brn_id[0]
list_load_percent_from_bus = []
for i in xrange(0, len(list_from_bus_no)):
_, dbl_temp = psspy.brnmsc(list_from_bus_no[i], list_to_bus_no[i], list_brn_id[i], string=str_rate_opt)
list_load_percent_from_bus.append(dbl_temp)
list_load_percent_from_bus = [round(j, int_round) for j in list_load_percent_from_bus]
list_load_percent_to_bus = []
for i in xrange(0, len(list_to_bus_no)):
_, dbl_temp = psspy.brnmsc(list_to_bus_no[i], list_from_bus_no[i], list_brn_id[i], string=str_rate_opt)
list_load_percent_to_bus.append(dbl_temp)
list_load_percent_to_bus = [round(j, int_round) for j in list_load_percent_to_bus]
list_data_from_bus = zip(list_from_bus_no, list_from_bus_names, list_load_percent_from_bus)
list_data_to_bus = zip(list_to_bus_no, list_to_bus_names, list_load_percent_to_bus)
list_data_all = list_data_from_bus + list_data_to_bus
# remove duplicates
list_data_all = list(dict.fromkeys(list_data_all))
# sort according to percentages
list_data_all = sorted(list_data_all, key=operator.itemgetter(-1, 0))
list_header = ['Bus No.', 'Bus Name', r'% of MVA Loading']
list_data_all = [list_header] + list_data_all
if str_path_csv_out:
with open(str_path_csv_out, 'wb') as fout:
w = csv.writer(fout)
w.writerows(list_data_all)
print('Output file : ' + str_path_csv_out)
else:
print(list_data_all)
if __name__ == '__main__':
# subsystem contains all buses
int_sid = -1
# for both interior subsystem branches and tie branches
int_tie = 3
# all non-transformer branches
int_flag = 2
str_rate_opt='PCTMVA'
# percentage rounding
int_round = 4
# the output CSV file path, change this as desired
# this puts it in the same folder as the script
str_path_csv_out = os.path.join(os.getcwd(), 'system_loading.csv')
showLoading(int_sid=int_sid, int_tie=int_tie, int_flag=int_flag, str_rate_opt=str_rate_opt, int_round=int_round, str_path_csv_out=str_path_csv_out)