不典型的UnboundLocalError

Question

这是代码：

def main(request):
    ..........
    div_list = soup.select('div')
    count = 0
    for div in div_list:
        count = count+1
    ..........

错误：

UnboundLocalError at /

local variable 'div_list' referenced before assignment

我无法理解它。我疯了吗？错误在哪里？