# Comma used to separate like in various cases:
# 1. a list of variable declarations
a, b, c = 20, 30, 80
# 2.a list of values
d = [20, 60, 80]
# 3.a list of parameters passed to a function
line(a, b, c, b)
line(d[0], d[1], d[2], d[1])