解析原始 HTTP 標頭

Question

我有一個原始 HTTP 字符串，我想表示對象中的字段。 有什么方法可以解析 HTTP 字符串中的各個標頭？

'GET /search?sourceid=chrome&ie=UTF-8&q=ergterst HTTP/1.1\r\nHost: www.google.com\r\nConnection: keep-alive\r\nAccept: application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5\r\nUser-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_6; en-US) AppleWebKit/534.13 (KHTML, like Gecko) Chrome/9.0.597.45 Safari/534.13\r\nAccept-Encoding: gzip,deflate,sdch\r\nAvail-Dictionary: GeNLY2f-\r\nAccept-Language: en-US,en;q=0.8\r\n
[...]'

Answer 1

更新：現在是 2019 年，所以我已經為 Python 3 重寫了這個答案，遵循一個試圖使用代碼的程序員的困惑評論。 原始 Python 2 代碼現在位於答案的底部。

標准庫中有很好的工具，既可用於解析 RFC 821 標頭，也可用於解析整個 HTTP 請求。 這是一個示例請求字符串（請注意，Python 將其視為一個大字符串，即使我們為了可讀性將其分成幾行），我們可以將其提供給我的示例：

request_text = (
    b'GET /who/ken/trust.html HTTP/1.1\r\n'
    b'Host: cm.bell-labs.com\r\n'
    b'Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3\r\n'
    b'Accept: text/html;q=0.9,text/plain\r\n'
    b'\r\n'
)

正如@TryPyPy 指出的那樣，您可以使用 Python 的電子郵件消息庫來解析標頭——盡管我們應該添加，一旦您完成創建，生成的Message對象就像一個標頭字典：

from email.parser import BytesParser
request_line, headers_alone = request_text.split(b'\r\n', 1)
headers = BytesParser().parsebytes(headers_alone)

print(len(headers))     # -> "3"
print(headers.keys())   # -> ['Host', 'Accept-Charset', 'Accept']
print(headers['Host'])  # -> "cm.bell-labs.com"

但這當然會忽略請求行，或者讓您自己解析它。 事實證明，有一個更好的解決方案。

如果您使用其BaseHTTPRequestHandler ，標准庫將為您解析 HTTP。 盡管它的文檔有點晦澀——標准庫中的整套 HTTP 和 URL 工具存在問題——但要讓它解析字符串，你所要做的就是 (a) 將你的字符串包裝在BytesIO()中，(b ) 讀取raw_requestline以便它准備好被解析，並且 (c) 捕獲在解析過程中發生的任何錯誤代碼，而不是讓它嘗試將它們寫回客戶端（因為我們沒有！）。

所以這是我們對標准庫類的特化：

from http.server import BaseHTTPRequestHandler
from io import BytesIO

class HTTPRequest(BaseHTTPRequestHandler):
    def __init__(self, request_text):
        self.rfile = BytesIO(request_text)
        self.raw_requestline = self.rfile.readline()
        self.error_code = self.error_message = None
        self.parse_request()

    def send_error(self, code, message):
        self.error_code = code
        self.error_message = message

再一次，我希望標准庫的人已經意識到 HTTP 解析應該以一種不需要我們編寫 9 行代碼來正確調用它的方式進行分解，但是你能做什么呢？ 下面是如何使用這個簡單的類：

# Using this new class is really easy!

request = HTTPRequest(request_text)

print(request.error_code)       # None  (check this first)
print(request.command)          # "GET"
print(request.path)             # "/who/ken/trust.html"
print(request.request_version)  # "HTTP/1.1"
print(len(request.headers))     # 3
print(request.headers.keys())   # ['Host', 'Accept-Charset', 'Accept']
print(request.headers['host'])  # "cm.bell-labs.com"

如果解析過程中出現錯誤， error_code不會是None ：

# Parsing can result in an error code and message

request = HTTPRequest(b'GET\r\nHeader: Value\r\n\r\n')

print(request.error_code)     # 400
print(request.error_message)  # "Bad request syntax ('GET')"

我更喜歡像這樣使用標准庫，因為我懷疑如果我嘗試使用正則表達式自己重新實現 Internet 規范，他們已經遇到並解決了可能會咬我的任何邊緣情況。

舊 Python 2 代碼

這是我第一次寫這個答案的原始代碼：

request_text = (
    'GET /who/ken/trust.html HTTP/1.1\r\n'
    'Host: cm.bell-labs.com\r\n'
    'Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3\r\n'
    'Accept: text/html;q=0.9,text/plain\r\n'
    '\r\n'
    )

和：

# Ignore the request line and parse only the headers

from mimetools import Message
from StringIO import StringIO
request_line, headers_alone = request_text.split('\r\n', 1)
headers = Message(StringIO(headers_alone))

print len(headers)     # -> "3"
print headers.keys()   # -> ['accept-charset', 'host', 'accept']
print headers['Host']  # -> "cm.bell-labs.com"

和：

from BaseHTTPServer import BaseHTTPRequestHandler
from StringIO import StringIO

class HTTPRequest(BaseHTTPRequestHandler):
    def __init__(self, request_text):
        self.rfile = StringIO(request_text)
        self.raw_requestline = self.rfile.readline()
        self.error_code = self.error_message = None
        self.parse_request()

    def send_error(self, code, message):
        self.error_code = code
        self.error_message = message

和：

# Using this new class is really easy!

request = HTTPRequest(request_text)

print request.error_code       # None  (check this first)
print request.command          # "GET"
print request.path             # "/who/ken/trust.html"
print request.request_version  # "HTTP/1.1"
print len(request.headers)     # 3
print request.headers.keys()   # ['accept-charset', 'host', 'accept']
print request.headers['host']  # "cm.bell-labs.com"

和：

# Parsing can result in an error code and message

request = HTTPRequest('GET\r\nHeader: Value\r\n\r\n')

print request.error_code     # 400
print request.error_message  # "Bad request syntax ('GET')"

Answer 2

mimetools自 Python 2.3 以來已被棄用，並已從 Python 3 (鏈接) 中完全刪除。

以下是在 Python 3 中應該如何操作：

import email
import io
import pprint

# […]

request_line, headers_alone = request_text.split('\r\n', 1)
message = email.message_from_file(io.StringIO(headers_alone))
headers = dict(message.items())
pprint.pprint(headers, width=160)

Answer 3

如果您剝離GET行，這似乎可以正常工作：

import mimetools
from StringIO import StringIO

he = "Host: www.google.com\r\nConnection: keep-alive\r\nAccept: application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5\r\nUser-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_6; en-US) AppleWebKit/534.13 (KHTML, like Gecko) Chrome/9.0.597.45 Safari/534.13\r\nAccept-Encoding: gzip,deflate,sdch\r\nAvail-Dictionary: GeNLY2f-\r\nAccept-Language: en-US,en;q=0.8\r\n"

m = mimetools.Message(StringIO(he))

print m.headers

解析示例並將第一行中的信息添加到對象的一種方法是：

import mimetools
from StringIO import StringIO

he = 'GET /search?sourceid=chrome&ie=UTF-8&q=ergterst HTTP/1.1\r\nHost: www.google.com\r\nConnection: keep-alive\r\n'

# Pop the first line for further processing
request, he = he.split('\r\n', 1)    

# Get the headers
m = mimetools.Message(StringIO(he))

# Add request information
m.dict['method'], m.dict['path'], m.dict['http-version'] = request.split()    

print m['method'], m['path'], m['http-version']
print m['Connection']
print m.headers
print m.dict

Answer 4

使用 python3.7、 urllib3.HTTPResponse 、 http.client.parse_headers ，並在此處使用 curl 標志說明：

curl -i -L -X GET "http://httpbin.org/relative-redirect/3" |  python -c '
import sys
from io import BytesIO
from urllib3 import HTTPResponse
from http.client import parse_headers

rawresponse = sys.stdin.read().encode("utf8")
redirects = []

while True:
    header, body = rawresponse.split(b"\r\n\r\n", 1)
    if body[:4] == b"HTTP":
        redirects.append(header)
        rawresponse = body
    else:
        break

f = BytesIO(header)
# read one line for HTTP/2 STATUSCODE MESSAGE
requestline = f.readline().split(b" ")
protocol, status = requestline[:2]
headers = parse_headers(f)

resp = HTTPResponse(body, headers=headers)
resp.status = int(status)

print("headers")
print(resp.headers)

print("redirects")
print(redirects)
'

輸出：

  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
100   215  100   215    0     0    435      0 --:--:-- --:--:-- --:--:--   435

headers
HTTPHeaderDict({'Connection': 'keep-alive', 'Server': 'gunicorn/19.9.0', 'Date': 'Thu, 20 Sep 2018 05:39:25 GMT', 'Content-Type': 'application/json', 'Content-Length': '215', 'Access-Control-Allow-Origin': '*', 'Access-Control-Allow-Credentials': 'true', 'Via': '1.1 vegur'})
redirects
[b'HTTP/1.1 302 FOUND\r\nConnection: keep-alive\r\nServer: gunicorn/19.9.0\r\nDate: Thu, 20 Sep 2018 05:39:24 GMT\r\nContent-Type: text/html; charset=utf-8\r\nContent-Length: 0\r\nLocation: /relative-redirect/2\r\nAccess-Control-Allow-Origin: *\r\nAccess-Control-Allow-Credentials: true\r\nVia: 1.1 vegur',
 b'HTTP/1.1 302 FOUND\r\nConnection: keep-alive\r\nServer: gunicorn/19.9.0\r\nDate: Thu, 20 Sep 2018 05:39:24 GMT\r\nContent-Type: text/html; charset=utf-8\r\nContent-Length: 0\r\nLocation: /relative-redirect/1\r\nAccess-Control-Allow-Origin: *\r\nAccess-Control-Allow-Credentials: true\r\nVia: 1.1 vegur',
 b'HTTP/1.1 302 FOUND\r\nConnection: keep-alive\r\nServer: gunicorn/19.9.0\r\nDate: Thu, 20 Sep 2018 05:39:24 GMT\r\nContent-Type: text/html; charset=utf-8\r\nContent-Length: 0\r\nLocation: /get\r\nAccess-Control-Allow-Origin: *\r\nAccess-Control-Allow-Credentials: true\r\nVia: 1.1 vegur']

筆記：

• https://urllib3.readthedocs.io/en/latest/reference/#urllib3.response.HTTPResponse
• parse_headers()

Answer 5

以pythonic的方式

request_text = (
    b'GET /who/ken/trust.html HTTP/1.1\r\n'
    b'Host: cm.bell-labs.com\r\n'
    b'Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3\r\n'
    b'Accept: text/html;q=0.9,text/plain\r\n'
    b'\r\n'
)

print({ k:v.strip() for k,v in [line.split(":",1) 
        for line in request_text.decode().splitlines() if ":" in line]})

Answer 6

它們是另一種處理標頭的更簡單和更安全的方法。 更面向對象。 無需手動解析。

簡短的演示。

1. 解析它們

從str ， bytes ， fp ， dict ， requests.Response ， email.Message ， httpx.Response ， urllib3.HTTPResponse 。

from requests import get
from kiss_headers import parse_it

response = get('https://www.google.fr')
headers = parse_it(response)

headers.content_type.charset  # output: ISO-8859-1
# Its the same as
headers["content-type"]["charset"]  # output: ISO-8859-1

2. 建造它們

這個

from kiss_headers import *

headers = (
    Host("developer.mozilla.org")
    + UserAgent(
        "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:50.0) Gecko/20100101 Firefox/50.0"
    )
    + Accept("text/html")
    + Accept("application/xhtml+xml")
    + Accept("application/xml", qualifier=0.9)
    + Accept(qualifier=0.8)
    + AcceptLanguage("en-US")
    + AcceptLanguage("en", qualifier=0.5)
    + AcceptEncoding("gzip")
    + AcceptEncoding("deflate")
    + AcceptEncoding("br")
    + Referer("https://developer.mozilla.org/testpage.html")
    + Connection(should_keep_alive=True)
    + UpgradeInsecureRequests()
    + IfModifiedSince("Mon, 18 Jul 2016 02:36:04 GMT")
    + IfNoneMatch("c561c68d0ba92bbeb8b0fff2a9199f722e3a621a")
    + CacheControl(max_age=0)
)

raw_headers = str(headers)

會變成

Host: developer.mozilla.org
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:50.0) Gecko/20100101 Firefox/50.0
Accept: text/html, application/xhtml+xml, application/xml; q="0.9", */*; q="0.8"
Accept-Language: en-US, en; q="0.5"
Accept-Encoding: gzip, deflate, br
Referer: https://developer.mozilla.org/testpage.html
Connection: keep-alive
Upgrade-Insecure-Requests: 1
If-Modified-Since: Mon, 18 Jul 2016 02:36:04 GMT
If-None-Match: "c561c68d0ba92bbeb8b0fff2a9199f722e3a621a"
Cache-Control: max-age="0"

Kiss-headers 庫的文檔。

Answer 7

在python3中

from email import message_from_string    
data = socket.recv(4096)
headers = message_from_string(str(data, 'ASCII').split('\r\n', 1)[1])
print(headers['Host'])

Answer 8

有什么方法可以解析 HTTP 字符串中的各個標頭？

我寫了一個可以返回字典對象的簡單函數，希望對你有所幫助。 ^_^

蟒蛇 3

def parse_request(request):
    raw_list = request.split("\r\n")
    request = {}
    for index in range(1, len(raw_list)):
        item = raw_list[index].split(":")
        if len(item) == 2:
            request.update({item[0].lstrip(' '): item[1].lstrip(' ')})
    return request


raw_request = 'GET /search?sourceid=chrome&ie=UTF-8&q=ergterst HTTP/1.1\r\nHost: www.google.com\r\nConnection: keep-alive\r\nAccept: application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5\r\nUser-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_6; en-US) AppleWebKit/534.13 (KHTML, like Gecko) Chrome/9.0.597.45 Safari/534.13\r\nAccept-Encoding: gzip,deflate,sdch\r\nAvail-Dictionary: GeNLY2f-\r\nAccept-Language: en-US,en;q=0.8\r\n'
request = parse_request(raw_request)
print(request)
print('\n')
print(request.keys())

輸出：

{'Host': 'www.google.com', 'Connection': 'keep-alive', 'Accept': 'application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5', 
'User-Agent': 'Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_6; en-US) AppleWebKit/534.13 (KHTML, like Gecko) Chrome/9.0.597.45 Safari/534.13', 'Accept-Encoding': 'gzip,deflate,sdch', 'Avail-Dictionary': 'GeNLY2f-', 'Accept-Language': 'en-US,en;q=0.8'}


dict_keys(['Host', 'Connection', 'Accept', 'User-Agent', 'Accept-Encoding', 'Avail-Dictionary', 'Accept-Language'])

Answer 9

從這個問題： How to parse raw HTTP request in Python 3?

以下是一些旨在正確解析 HTTP 協議的 Python 包：

• https://dpkt.readthedocs.io/en/latest/api/api_auto.html#module-dpkt.http
• https://h11.readthedocs.io/en/latest/
• https://github.com/benoitc/http-parser/（C后端）
• https://github.com/MagicStack/httptools （基於NodeJS的C后端）
• https://github.com/silentsignal/netlib-offline （無恥插件）