Python 为什么错误信息可以'；不能记录到指定的文件中吗？

平台：Debian8+Python3.4+Scrapy1.3.2 这是我的蜘蛛从yahoo.com下载的一些URL

import scrapy  
import csv

class TestSpider(scrapy.Spider):  
    name = "quote"  
    allowed_domains = ["yahoo.com"] 
    start_urls = ['url1','url2','url3',,,,'urls100']

    def parse(self, response):  
        filename = response.url.split("=")[1]  
        open('/tmp/'+filename+'.csv', 'wb').write(response.body)  

执行时会出现一些错误信息：

2017-02-19 21:28:27 [scrapy.spidermiddlewares.httperror] INFO: Ignoring response 
<404 https://chart.yahoo.com/table.csv?s=GLU>: HTTP status code is not handled or not allowed

为什么会显示错误信息，如
2017-02-19 21:28:27[scrapy.spidermiddleware.httperror]信息：忽略响应 ：未处理或不允许HTTP状态代码 无法记录在/home/log.txt中

想一想eLRuLL，我添加了handle\u httpstatus\u list=[404]

import scrapy
import csv

import logging
from scrapy.utils.log import configure_logging
configure_logging(install_root_handler=False)
logging.basicConfig(
    filename='/home/log.txt',
    format='%(levelname)s: %(message)s',
    level=logging.INFO
)

class TestSpider(scrapy.Spider):
    handle_httpstatus_list = [404]
    name = "quote"
    allowed_domains = ["yahoo.com"]
    start_urls = ['url1','url2','url3',,,,'url100']

    def parse(self, response):
        filename = response.url.split("=")[1]
        open('/tmp/'+filename+'.csv', 'wb').write(response.body)

---

错误信息仍然无法记录到/home/log.txt文件中，为什么

使用spider上的

handle\u httpstatus\u列表

属性来处理

404

状态：

class TestSpider(scrapy.Spider):
    handle_httpstatus_list = [404]

class TestSpider(scrapy.Spider):
    handle_httpstatus_list = [404]