pySim-prog: add python docstring for read_params_csv

Change-Id: I098ff56ef38208f2f321194625ff4279ece2023c
---
M pySim-prog.py
1 file changed, 6 insertions(+), 0 deletions(-)

diff --git a/pySim-prog.py b/pySim-prog.py
index f106018..b3919ee 100755
--- a/pySim-prog.py
+++ b/pySim-prog.py
@@ -584,6 +584,12 @@
 
 
 def read_params_csv(opts, imsi=None, iccid=None):
+    """
+    Read the card parameters from a CSV file. This function will generate the
+    same dictionary that gen_parameters would generate from parameters passed as
+    commandline arguments.
+    """
+
     row = find_row_in_csv_file(opts.read_csv, opts.num, iccid=iccid, imsi=imsi)
     if row is not None:
         row['mcc'] = row.get('mcc', mcc_from_imsi(row.get('imsi')))

