Question

我有一个简单的Python脚本，可以从reddit中提取帖子并在Twitter上发布。不幸的是，今晚它开始出现我所假设的问题，因为有人在reddit上的标题有格式问题。我收到的错误是：

  File "redditbot.py", line 82, in <module>
  main()
 File "redditbot.py", line 64, in main
 tweeter(post_dict, post_ids)
 File "redditbot.py", line 74, in tweeter
 print post+" "+post_dict[post]+" #python"
 UnicodeEncodeError: 'ascii' codec can't encode character u'\u201c' in  position 34: ordinal not in range(128)

这是我的剧本：

# encoding=utf8
import praw
import json
import requests
import tweepy
import time
import urllib2
import sys
reload(sys)
sys.setdefaultencoding('utf8')

access_token = 'hidden'
access_token_secret = 'hidden'
consumer_key = 'hidden'
consumer_secret = 'hidden'


def strip_title(title):
    if len(title) < 75:
    return title
else:
    return title[:74] + "..."

def tweet_creator(subreddit_info):
post_dict = {}
post_ids = []
print "[bot] Getting posts from Reddit"
for submission in subreddit_info.get_hot(limit=2000):
    post_dict[strip_title(submission.title)] = submission.url
    post_ids.append(submission.id)
print "[bot] Generating short link using goo.gl"
mini_post_dict = {}
for post in post_dict:
    post_title = post
    post_link = post_dict[post]

    mini_post_dict[post_title] = post_link
return mini_post_dict, post_ids

def setup_connection_reddit(subreddit):
print "[bot] setting up connection with Reddit"
r = praw.Reddit('PythonReddit PyReTw'
            'monitoring %s' %(subreddit))
subreddit = r.get_subreddit('python')
return subreddit



def duplicate_check(id):
found = 0
with open('posted_posts.txt', 'r') as file:
    for line in file:
        if id in line:
            found = 1
return found

def add_id_to_file(id):
with open('posted_posts.txt', 'a') as file:
    file.write(str(id) + "\n")

def main():
subreddit = setup_connection_reddit('python')
post_dict, post_ids = tweet_creator(subreddit)
tweeter(post_dict, post_ids)

def tweeter(post_dict, post_ids):
auth = tweepy.OAuthHandler(consumer_key, consumer_secret)
auth.set_access_token(access_token, access_token_secret)
api = tweepy.API(auth)
for post, post_id in zip(post_dict, post_ids):
    found = duplicate_check(post_id)
    if found == 0:
        print "[bot] Posting this link on twitter"
        print post+" "+post_dict[post]+" #python"
        api.update_status(post+" "+post_dict[post]+" #python")
        add_id_to_file(post_id)
        time.sleep(3000)
    else:
        print "[bot] Already posted"

if __name__ == '__main__':
main()

非常感谢任何帮助 - 提前感谢！

Answer 1

考虑这个简单的程序：

print(u'\u201c' + "python")

如果你尝试打印到终端（使用适当的字符编码），你得到

“python

但是，如果您尝试将输出重定向到文件，则会得到UnicodeEncodeError。

script.py > /tmp/out
Traceback (most recent call last):
  File "/home/unutbu/pybin/script.py", line 4, in <module>
    print(u'\u201c' + "python")
UnicodeEncodeError: 'ascii' codec can't encode character u'\u201c' in position 0: ordinal not in range(128)

当您打印到终端时，Python使用终端的字符编码来编码unicode。（终端只能打印字节，因此必须对unicode进行编码才能打印。）

当您将输出重定向到文件时，Python无法确定字符编码，因为文件没有声明的编码。因此，默认情况下，Python2在写入文件之前使用ascii编码隐式编码所有unicode。由于u'\u201c'无法进行ascii编码，因此UnicodeEncodeError。（只有前127个unicode代码点可以用ascii编码）。

Why Print Fails wiki详细说明了这个问题。

要解决此问题，请首先避免添加unicode和字节字符串。这会导致使用Python2中的ascii编解码器进行隐式转换，以及Python3中的异常。为了面向未来的代码，最好是明确的。例如，在格式化和打印字节之前显式编码post：

post = post.encode('utf-8')
print('{} {} #python'.format(post, post_dict[post]))

Answer 2

您正在尝试将unicode字符串打印到终端（或者可能是通过IO重定向打印文件），但终端（或文件系统）使用的编码是ASCII。由于此Python尝试将其从unicode表示转换为ASCII，但由于代码点u'\u201c'（“）无法用ASCII表示，因此失败。您的代码实际上是这样做的：

>>> print u'\u201c'.encode('ascii')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
UnicodeEncodeError: 'ascii' codec can't encode character u'\u201c' in position 0: ordinal not in range(128)

您可以尝试转换为UTF-8：

print (post + " " + post_dict[post] + " #python").encode('utf8')

或像这样转换为ASCII：

print (post + " " + post_dict[post] + " #python").encode('ascii', 'replace')

将用?替换无效的ASCII字符。

另一种方法，如果您正在打印以进行调试，则可以打印字符串的repr：

print repr(post + " " + post_dict[post] + " #python")

会输出如下内容：

>>> s = 'string with \u201cLEFT DOUBLE QUOTATION MARK\u201c'
>>> print repr(s)
u'string with \u201cLEFT DOUBLE QUOTATION MARK\u201c'

Answer 3

问题可能是串联上混合字节串和unicode字符串引起的。作为使用u为所有字符串文字添加前缀的替代方法，可能

from __future__ import unicode_literals

为您解决问题。请参阅here以获得更深入的解释，并确定它是否适合您。

收到UnicodeEncodeError的Python脚本：＆＃39; ascii＆＃39;编解码器无法对字符

3 个答案: