If, elif, else conditions

I was dealing with CodingBat problems to learn better and more efficiently and the problem I've faced was:

Given 2 int values, return True if one is negative and one is positive. Except if the parameter "negative" is True, then return True only if both are negative.


pos_neg(1, -1, False) → True
pos_neg(-1, 1, False) → True
pos_neg(-4, -5, True) → True

I wrote that code to run the desired process

def pos_neg(a, b, negative):
  if (a<0 and b>0) or (a>0 and b<0):
    return True
  elif negative and (a<0 and b<0)
    return True
  else:
    return False

but I get

Compile problems:


invalid syntax (line 4)

as an Error. Solution given by CondaBat is:

def pos_neg(a, b, negative):
  if negative:
    return (a < 0 and b < 0)
  else:
    return ((a < 0 and b > 0) or (a > 0 and b < 0))

I see that the example code given by is faster and more efficent compared to mine but I can't see why my elif statement returns an error.