读取word文档里某段文字，查找字符所在位置，提取改文字。

注意中文需要转化。name = old_text.encode("gbk")

def sen(i, str1, str2,x,y):
    old_text = doc.paragraphs[i].text
    name = old_text.encode("gbk")  
    older1 = old_text.find(u'{}'.format(str1))+x
    older2 = old_text.find(u'{}'.format(str2),older1+y)
    older = old_text[older1:older2]
    return older 

older_sum_sub = sen(31, "周末", "天",3,1)

print(older_sum_sub)