Don't know how to solve the syntax error


def printExtendedBasePattern(n, 'o', '-'):

pattern = []

for index in range(n):
    pattern.append(n * ['-'])

for line in range(n):
    pattern[line][line] = 'o'
    pattern[line][len(pattern) - 1 - line] = 'o'

for row in pattern:
    print (' '.join(row))

print(printBasePattern(6, 'o', '-'))

Based on the battleship code, I write a new code. This is my code, whenever I want to run it, it always says that there is an invalid syntax error in the parameter part.


What is the goal of this line? Please explain your reasoning. Thank you.