将空白替换为：

url = url.replace(" ", "%20")

如果问题出在空格上的话。

空格是不允许在网址，我删除了他们，它似乎是现在工作：

import urllib.request
start_url = "https://devbusiness.un.org/solr-sitesearch-output/10//0/ds_field_last_updated/desc?bundle_fq =procurement_notice&sm_vid_Institutions_fq=&sm_vid_Procurement_Type_fq=&sm_vid_Countries_fq=&sm_vid_Sectors_fq= &sm_vid_Languages_fq=English&sm_vid_Notice_Type_fq=&deadline_multifield_fq=&ts_field_project_name_fq=&label_fq=&sm_field_db_ref_no__fq=&sm_field_loan_no__fq=&dm_field_deadlineFrom_fq=&dm_field_deadlineTo_fq =&ds_field_future_posting_dateFrom_fq=&ds_field_future_posting_dateTo_fq=&bm_field_individual_consulting_fq="
url = start_url.replace(" ","")
source = urllib.request.urlopen(url).read()

Solr搜索字符串可能会变得很奇怪。最好在发出请求之前使用'quote'方法对字符进行编码。请参见下面的示例：

from urllib.parse import quote

start_url = "https://devbusiness.un.org/solr-sitesearch-output/10//0/ds_field_last_updated/desc?bundle_fq =procurement_notice&sm_vid_Institutions_fq=&sm_vid_Procurement_Type_fq=&sm_vid_Countries_fq=&sm_vid_Sectors_fq= &sm_vid_Languages_fq=English&sm_vid_Notice_Type_fq=&deadline_multifield_fq=&ts_field_project_name_fq=&label_fq=&sm_field_db_ref_no__fq=&sm_field_loan_no__fq=&dm_field_deadlineFrom_fq=&dm_field_deadlineTo_fq =&ds_field_future_posting_dateFrom_fq=&ds_field_future_posting_dateTo_fq=&bm_field_individual_consulting_fq="
    
source = urllib.request.urlopen(quote(start_url)).read()

迟做总比不做好...

你现在可能已经知道了，但让我们把它写在这里。
URL中不能有任何 * 空格 * 字符，但在bundle_fqedm_field_deadlineTo_fq之后有2个
把这些拿掉你就可以走了

就像错误信息所说的，在你的url中有一些control characters，顺便说一句，这似乎不是一个有效的。

你需要在URL中使用encode the control characters。特别是空格需要编码为%20。

首先解析url，然后对url元素进行编码就可以了。

import urllib.request
from urllib.parse import urlparse, quote

def make_safe_url(url: str) -> str:
    """
    Returns a parsed and quoted url
    """
    _url = urlparse(url)
    url = _url.scheme + "://" + _url.netloc + quote(_url.path) + "?" + quote(_url.query)
    return url

start_url = "https://devbusiness.un.org/solr-sitesearch-output/10//0/ds_field_last_updated/desc?bundle_fq =procurement_notice&sm_vid_Institutions_fq=&sm_vid_Procurement_Type_fq=&sm_vid_Countries_fq=&sm_vid_Sectors_fq= &sm_vid_Languages_fq=English&sm_vid_Notice_Type_fq=&deadline_multifield_fq=&ts_field_project_name_fq=&label_fq=&sm_field_db_ref_no__fq=&sm_field_loan_no__fq=&dm_field_deadlineFrom_fq=&dm_field_deadlineTo_fq =&ds_field_future_posting_dateFrom_fq=&ds_field_future_posting_dateTo_fq=&bm_field_individual_consulting_fq="
start_url = make_safe_url(start_url)
source = urllib.request.urlopen(start_url).read()

尽管url中有双正斜杠和空格，代码仍返回JSON文档。