join elements from two splits

[dwiga]

I want to join two splitted string,

a = "a,b,c"
b = "1,2,3"

spla = a.split(",")
splb = b.split(",")
for arra, arrb in spla, splb:
  print(arra + "-" + arrb)

what I get is

Error:
Traceback (most recent call last):
  File "python", line 6, in <module>
ValueError: too many values to unpack (expected 2)

help to get rid this.,
thank you in advance!