Return the amount of water (in liter) in a persons body

def calculate_bw(age, weight, height, sex):
  """Return the amount of water (in liter) in a persons body"""
  if sex: # female
    return 0.203 - (0.07 * age) + (0.1069 * height) + (0.2466 * weight)
  else: # male
    return 2.447 - (0.09516 * age) + (0.1074 * height) + (0.3362 * weight)