python 中 for 循环的 readlines() 错误

Question

这个错误很难描述，因为我无法弄清楚循环是如何影响 readline() 和 readlines() 方法的。当我尝试使用前者时，我遇到了这些意外的 Traceback 错误。当我尝试后者时，我的代码运行s 没有任何反应。我确定错误位于前八行。 Topics.txt 文件的前几行已发布。

Code

import requests
from html.parser import HTMLParser
from bs4 import BeautifulSoup

Url = "https://ritetag.com/best-hashtags-for/"
Topicfilename = "Topics.txt"
Topicfile = open(Topicfilename, 'r')
Line = Topicfile.readlines()
Linenumber = 0
for Line in Topicfile:
    Linenumber += 1
    print("Reading line", Linenumber)

    Topic = Line
    Newtopic = Topic.strip("\n").replace(' ', '').replace(',', '')
    print(Newtopic)
    Link = Url.join(Newtopic)
    print(Link)
    Sourcecode = requests.get(Link)

当我在这里运行这个位时，它打印 URL 前面是 line.For 示例的第一个字符，它打印为 2https://ritetag.com/best-hashtags-for/4https://ritetag.com/best-hashtags-for/Hhttps://ritetag.com/best-hashtags-for/ 等 24 小时健身。

Topics.txt

21 世纪福克斯
24 小时健身
2K 游戏
3M

Full Error

Reading line 1 24HourFitness 2https://ritetag.com/best-hashtags-for/4https://ritetag.com/best-hashtags-for/Hhttps://ritetag.com/best-hashtags-for/ohttps://ritetag.com/best-hashtags-for/uhttps://ritetag.com/best-hashtags-for/rhttps://ritetag.com/best-hashtags-for/Fhttps://ritetag.com/best-hashtags-for/ihttps://ritetag.com/best-hashtags-for/thttps://ritetag.com/best-hashtags-for/nhttps://ritetag.com/best-hashtags-for/ehttps://ritetag.com/best-hashtags-for/shttps://ritetag.com/best-hashtags-for/s

Traceback (most recent call last): File "C:\Users\Caden\Desktop\Programs\LususStudios\AutoDealBot\HashtagScanner.py", line 17, in Sourcecode = requests.get(Link) File "C:\Python34\lib\site-packages\requests-2.10.0-py3.4.egg\requests\api.py", line 71, in get return request('get', url, params=params, **kwargs) File "C:\Python34\lib\site-packages\requests-2.10.0-py3.4.egg\requests\api.py", line 57, in request return session.request(method=method, url=url, **kwargs) File "C:\Python34\lib\site-packages\requests-2.10.0-py3.4.egg\requests\sessions.py", line 475, in request resp = self.send(prep, **send_kwargs) File "C:\Python34\lib\site-packages\requests-2.10.0-py3.4.egg\requests\sessions.py", line 579, in send adapter = self.get_adapter(url=request.url) File "C:\Python34\lib\site-packages\requests-2.10.0-py3.4.egg\requests\sessions.py", line 653, in get_adapter raise InvalidSchema("No connection adapters were found for '%s'" % url) requests.exceptions.InvalidSchema: No connection adapters were found for '2https://ritetag.com/best-hashtags-for/4https://ritetag.com/best-hashtags-for/Hhttps://ritetag.com/best-hashtags-for/ohttps://ritetag.com/best-hashtags-for/uhttps://ritetag.com/best-hashtags-for/rhttps://ritetag.com/best-hashtags-for/Fhttps://ritetag.com/best-hashtags-for/ihttps://ritetag.com/best-hashtags-for/thttps://ritetag.com/best-hashtags-for/nhttps://ritetag.com/best-hashtags-for/ehttps://ritetag.com/best-hashtags-for/shttps://ritetag.com/best-hashtags-for/s'

Answer 1

首先，python 惯例是将所有变量名小写。

其次，当你开始读取所有行时，你正在耗尽文件指针，然后继续循环遍历文件。

尝试简单地打开文件，然后遍历它

linenumber = 0
with open("Topics.txt") as topicfile:
    for line in topicfile:
        # do work 
        linenumber += 1

然后，回溯中的问题，如果你仔细观察，你正在建立这个很长的 url 字符串，那绝对不是 url，所以请求会抛出错误

InvalidSchema: No connection adapters were found for '2https://ritetag.com/best-hashtags-for/4https://ritetag.com/...

并且你可以调试看到 Url.join(Newtopic) 是 "interleaving" Newtopic 列表的每个字符之间的 Url 字符串，也就是 str.join会做

Answer 2

我认为有两个问题：

您似乎在迭代 Topicfile 而不是 Topicfile.readLines()。
Url.join(Newtopic) 没有返回您认为的那样。 .join 获取一个列表（在本例中，字符串是一个字符列表）并将在每个列表之间插入 Url。

这是解决了这些问题的代码：

import requests

Url = "https://ritetag.com/best-hashtags-for/"
Topicfilename = "topics.txt"
Topicfile = open(Topicfilename, 'r')
Lines = Topicfile.readlines()
Linenumber = 0
for Line in Lines:
    Linenumber += 1
    print("Reading line", Linenumber)

    Topic = Line
    Newtopic = Topic.strip("\n").replace(' ', '').replace(',', '')
    print(Newtopic)
    Link = '{}{}'.format(Url, Newtopic)
    print(Link)
    Sourcecode = requests.get(Link)

顺便说一句，我还建议使用小写变量名，因为驼峰式大小写通常保留给 Python 中的 class 名称 :)

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