Python 如何通过限制后重试正确获取API
我正在尝试使用以下代码获取ArXiv API:Python 如何通过限制后重试正确获取API,python,request,Python,Request,我正在尝试使用以下代码获取ArXiv API: import urllib.request import pandas as pd import xml.etree.ElementTree as ET OAI = "{http://www.openarchives.org/OAI/2.0/}" ARXIV = "{http://arxiv.org/OAI/arXiv/}" def harvest(arxiv): df = pd.DataFrame(columns=("title",
import urllib.request
import pandas as pd
import xml.etree.ElementTree as ET
OAI = "{http://www.openarchives.org/OAI/2.0/}"
ARXIV = "{http://arxiv.org/OAI/arXiv/}"
def harvest(arxiv):
df = pd.DataFrame(columns=("title", "abstract", "categories"))
base_url = "http://export.arxiv.org/oai2?verb=ListRecords&"
url = (base_url +
"from=2012-01-01&until=2019-01-01&" +
"metadataPrefix=arXiv&set=%s"%arxiv)
while True:
print("fetching", url)
response = urllib.request.urlopen(url)
xml = response.read()
root = ET.fromstring(xml)
for record in root.find(OAI+'ListRecords').findall(OAI+"record"):
meta = record.find(OAI+'metadata')
info = meta.find(ARXIV+"arXiv")
categories = info.find(ARXIV+"categories").text
contents = {'title': info.find(ARXIV+"title").text,
'abstract':
info.find(ARXIV+"abstract").text.strip(),
'categories': categories.split(),
}
df = df.append(contents, ignore_index=True)
token = root.find(OAI+'ListRecords').find(OAI+"resumptionToken")
if token is None or token.text is None:
break
else:
url = base_url + "resumptionToken=%s"%(token.text)
return df
df_hep_th = harvest("physics:hep-th")
df_hep_th.to_csv('df_hep_th.csv', sep=',', encoding='utf-8')
我每次得到1000篇论文,并将它们附加到一个数据框上。然后我将df保存为csv
我曾经成功地尝试过这段代码,例如,为了得到“physics:hep-ex”类别的结果。起初它工作得很好,但现在我遇到了这个错误,我无法解决它:
File "C:\Users\my_user\Anaconda3\lib\urllib\request.py", line 649, in
http_error_default
raise HTTPError(req.full_url, code, msg, hdrs, fp)
HTTPError: Retry after specified interval
问题的出现是因为您在很短的时间间隔内执行了太多的请求。看看HTTP文档。您应该做的是检索这段时间间隔
t
,当您出现错误时,使用一些延迟函数等待t
秒,然后继续运行循环。非常感谢,如果我在这段时间内有了:try:response=urllib.request.urlopen(url),问题就解决了除了urllib.error.HTTPError作为e:if e.code==503:to=int(e.hdrs.get(“在之后重试”,30))打印(“get 503.在{0:d}秒之后重试。”.format(to))time.sleep(to)continue其他:引发