add python_requests.py
xianhu
parent
9441818c24
commit
3ea12f7f85
|
|
@ -15,6 +15,8 @@
|
|||
### python_sqlalchemy.py: 作为一个Pythoner，不会SQLAlchemy都不好意思跟同行打招呼！
|
||||
|
||||
### python_oneline.py: 几个小例子告诉你, 一行Python代码能干哪些事
|
||||
|
||||
### python_requests.py: Python中最好用的爬虫库Requests代码实例
|
||||
============================================================
|
||||
|
||||
### 您可以fork该项目,并在修改后提交Pull request
|
||||
|
|
|
|||
|
|
@ -0,0 +1,216 @@
|
|||
# _*_ coding: utf-8 _*_
|
||||
|
||||
"""
|
||||
python_requests.py by xianhu
|
||||
"""
|
||||
|
||||
import requests
|
||||
|
||||
# 尝试获取某个网页, 这里的r是一个Response对象
|
||||
r = requests.get("https://github.com/timeline.json")
|
||||
print(type(r))
|
||||
|
||||
# Requests简便的API意味着所有HTTP请求类型都是显而易见的
|
||||
r1 = requests.post("http://httpbin.org/post")
|
||||
r2 = requests.put("http://httpbin.org/put")
|
||||
r3 = requests.delete("http://httpbin.org/delete")
|
||||
r4 = requests.head("http://httpbin.org/get")
|
||||
r5 = requests.options("http://httpbin.org/get")
|
||||
|
||||
# 传递URL参数: 字典
|
||||
payload = {"key1": "value1", "key2": "value2"}
|
||||
r = requests.get("http://httpbin.org/get", params=payload)
|
||||
print(r.url) # http://httpbin.org/get?key2=value2&key1=value1
|
||||
|
||||
# 传递URL参数: 字典里带有列表
|
||||
payload = {"key1": "value1", "key2": ["value2", "value3"]}
|
||||
r = requests.get("http://httpbin.org/get", params=payload)
|
||||
print(r.url) # http://httpbin.org/get?key1=value1&key2=value2&key2=value3
|
||||
|
||||
# 获取正常内容
|
||||
r = requests.get("https://github.com/timeline.json")
|
||||
print(r.text) # "[{"repository":{"open_issues":0,"url":"https://github.com/...
|
||||
print(r.encoding) # "utf-8"
|
||||
|
||||
# Requests会自动解码来自服务器的内容(基于HTTP头部对响应的编码作出有根据的推测), 或者你自己更改
|
||||
r.encoding = "ISO-8859-1"
|
||||
print(r.text) # 此时使用新的r.encoding新值
|
||||
|
||||
# 二进制响应内容, Requests会自动为你解码 gzip 和 deflate 传输编码的响应数据
|
||||
print(r.content) # b"[{"repository":{"open_issues":0,"url":"https://github.com/...
|
||||
|
||||
# JSON 响应内容, Requests中也有一个内置的JSON解码器
|
||||
print(r.json()) # [{u"repository": {u"open_issues": 0, u"url": "https://github.com/...
|
||||
|
||||
# 原始响应内容: 获取来自服务器的原始套接字响应
|
||||
r = requests.get("https://github.com/timeline.json", stream=True)
|
||||
print(r.raw) # <requests.packages.urllib3.response.HTTPResponse object at 0x101194810>
|
||||
print(r.raw.read(10)) # "\x1f\x8b\x08\x00\x00\x00\x00\x00\x00\x03"
|
||||
|
||||
# 但一般情况下, 应该以下面的模式将文本流保存到文件
|
||||
with open("test", "wb") as fd:
|
||||
for chunk in r.iter_content(chunk_size=256):
|
||||
fd.write(chunk)
|
||||
|
||||
# 定制请求头: 一个字典
|
||||
headers = {"user-agent": "my-app/0.0.1"}
|
||||
r = requests.get("https://api.github.com/some/endpoint", headers=headers)
|
||||
print(r.request.headers) # 获取该请求的头部
|
||||
|
||||
# 更加复杂的POST请求: 表单
|
||||
payload = {"key1": "value1", "key2": "value2"}
|
||||
r = requests.post("http://httpbin.org/post", data=payload)
|
||||
print(r.text)
|
||||
|
||||
# POST一个多部分编码(Multipart-Encoded)的文件
|
||||
files = {"file": open("report.xls", "rb")}
|
||||
r = requests.post("http://httpbin.org/post", files=files)
|
||||
print(r.text)
|
||||
|
||||
# 你可以显式地设置文件名, 文件类型和请求头
|
||||
files = {"file": ("report.xls", open("report.xls", "rb"), "application/vnd.ms-excel", {"Expires": "0"})}
|
||||
r = requests.post("http://httpbin.org/post", files=files)
|
||||
print(r.text)
|
||||
|
||||
# 你也可以发送作为文件来接收的字符串
|
||||
files = {"file": ("report.csv", "some,data,to,send\nanother,row,to,send\n")}
|
||||
r = requests.post("http://httpbin.org/post", files=files)
|
||||
print(r.text)
|
||||
|
||||
# 响应状态码
|
||||
r = requests.get("http://httpbin.org/get")
|
||||
print(r.status_code) # 200
|
||||
print(r.status_code == requests.codes.ok) # True 响应状态码查询
|
||||
|
||||
# 如果发送了一个错误请求(4XX客户端错误, 或5XX服务器错误响应), 可以通过 Response.raise_for_status() 来抛出异常:
|
||||
bad_r = requests.get("http://httpbin.org/status/404")
|
||||
print(bad_r.status_code) # 404
|
||||
bad_r.raise_for_status()
|
||||
# Traceback (most recent call last):
|
||||
# File "requests/models.py", line 832, in raise_for_status
|
||||
# raise http_error
|
||||
# requests.exceptions.HTTPError: 404 Client Error
|
||||
|
||||
# 响应头, 一个Python字典形式展示的服务器响应头, HTTP头部是大小写不敏感的
|
||||
print(r.headers)
|
||||
# {
|
||||
# "content-encoding": "gzip",
|
||||
# "transfer-encoding": "chunked",
|
||||
# "connection": "close",
|
||||
# "server": "nginx/1.0.4",
|
||||
# "x-runtime": "148ms",
|
||||
# "etag": "e1ca502697e5c9317743dc078f67693f",
|
||||
# "content-type": "application/json"
|
||||
# }
|
||||
print(r.headers["Content-Type"]) # "application/json"
|
||||
print(r.headers.get("content-type")) # "application/json"
|
||||
|
||||
# Cookie: 如果某个响应中包含一些 cookie
|
||||
r = requests.get("http://example.com/some/cookie/setting/url")
|
||||
print(r.cookies["example_cookie_name"]) # "example_cookie_value"
|
||||
|
||||
# 要想发送你的cookies到服务器, 可以使用cookies参数, 一个字典
|
||||
cookies = dict(cookies_are="working")
|
||||
r = requests.get("http://httpbin.org/cookies", cookies=cookies)
|
||||
print(r.text)
|
||||
|
||||
# 会话对象: 会话对象让你能够跨请求保持某些参数, 它也会在同一个 Session 实例发出的所有请求之间保持cookie
|
||||
s = requests.Session()
|
||||
s.get("http://httpbin.org/cookies/set/sessioncookie/123456789")
|
||||
r = s.get("http://httpbin.org/cookies")
|
||||
print(r.text) # '{"cookies": {"sessioncookie": "123456789"}}'
|
||||
|
||||
# 会话也可用来为请求方法提供缺省数据, 这是通过为会话对象的属性提供数据来实现的
|
||||
s = requests.Session()
|
||||
s.auth = ("user", "pass")
|
||||
s.headers.update({"x-test": "true"})
|
||||
s.get("http://httpbin.org/headers", headers={"x-test2": "true"}) # both "x-test" and "x-test2" are sent
|
||||
|
||||
# 不过需要注意, 就算使用了会话, 方法级别的参数也不会被跨请求保持
|
||||
# 下面的例子只会和第一个请求发送cookie, 而非第二个
|
||||
s = requests.Session()
|
||||
r = s.get("http://httpbin.org/cookies", cookies={"from-my": "browser"})
|
||||
print(r.text) # '{"cookies": {"from-my": "browser"}}'
|
||||
r = s.get("http://httpbin.org/cookies")
|
||||
print(r.text) # '{"cookies": {}}'
|
||||
# 如果你要手动为会话添加 cookie, 就是用 Cookie utility 函数来操纵Session.cookies
|
||||
|
||||
# 会话还可以用作前后文管理器
|
||||
with requests.Session() as s:
|
||||
s.get("http://httpbin.org/cookies/set/sessioncookie/123456789")
|
||||
|
||||
# 重定向与请求历史, 默认情况下, 除了HEAD, Requests会自动处理所有重定向
|
||||
# 可以使用响应对象的history方法来追踪重定向
|
||||
# Response.history 是一个 Response 对象的列表, 为了完成请求而创建了这些对象. 这个对象列表按照从最老到最近的请求进行排序
|
||||
r = requests.get("http://github.com")
|
||||
print(r.status_code) # 200
|
||||
print(r.history) # [<Response [301]>]
|
||||
|
||||
# 如果你使用的是GET、OPTIONS、POST、PUT、PATCH 或者 DELETE, 那么你可以通过 allow_redirects 参数禁用重定向处理
|
||||
r = requests.get("http://github.com", allow_redirects=False)
|
||||
print(r.status_code) # 301
|
||||
print(r.history) # []
|
||||
|
||||
# 如果你使用了HEAD, 你也可以启用重定向
|
||||
r = requests.head("http://github.com", allow_redirects=True)
|
||||
print(r.history) # [<Response [301]>]
|
||||
|
||||
# 超时, 设置timeout参数
|
||||
requests.get("http://github.com", timeout=0.001)
|
||||
# Traceback (most recent call last):
|
||||
# File "<stdin>", line 1, in <module>
|
||||
# requests.exceptions.Timeout: HTTPConnectionPool(host="github.com", port=80): Request timed out. (timeout=0.001)
|
||||
|
||||
# 注意: timeout仅对连接过程有效, 与响应体的下载无关
|
||||
# timeout并不是整个下载响应的时间限制, 而是如果服务器在timeout秒内没有应答, 将会引发一个异常
|
||||
# 更精确地说, 是在 timeout 秒内没有从基础套接字上接收到任何字节的数据时
|
||||
requests.get("https://github.com", timeout=5)
|
||||
# 这一 timeout 值将会用作 connect 和 read 二者的 timeout
|
||||
# 如果要分别制定, 就传入一个元组
|
||||
requests.get("https://github.com", timeout=(3.05, 27))
|
||||
|
||||
# 错误与异常: 遇到网络问题(如: DNS 查询失败、拒绝连接等)时, Requests 会抛出一个 ConnectionError 异常
|
||||
# 如果 HTTP 请求返回了不成功的状态码, Response.raise_for_status() 会抛出一个 HTTPError 异常
|
||||
# 若请求超时, 则抛出一个 Timeout 异常
|
||||
# 若请求超过了设定的最大重定向次数, 则会抛出一个 TooManyRedirects 异常
|
||||
# 所有Requests显式抛出的异常都继承自 requests.exceptions.RequestException
|
||||
|
||||
# SSL证书验证, verify设置为True表示检查证书, 设置为False表示忽略证书
|
||||
requests.get("https://kennethreitz.com", verify=True) # 未设置SSL证书, 抛出异常
|
||||
# requests.exceptions.SSLError: hostname "kennethreitz.com" doesn"t match either of "*.herokuapp.com", "herokuapp.com"
|
||||
requests.get("https://github.com", verify=True) # <Response [200]>, 已设置SSL证书
|
||||
# 对于私有证书，你也可以传递一个 CA_BUNDLE 文件的路径给 verify
|
||||
|
||||
# 你也可以指定一个本地证书用作客户端证书, 可以是单个文件（包含密钥和证书）或一个包含两个文件路径的元组:
|
||||
requests.get("https://kennethreitz.com", cert=("/path/server.crt", "/path/key"))
|
||||
requests.get("https://kennethreitz.com", cert="/wrong_path/server.pem")
|
||||
# SSLError: [Errno 336265225] _ssl.c:347: error:140B0009:SSL routines:SSL_CTX_use_PrivateKey_file:PEM lib
|
||||
# 警告: 本地证书的私有 key 必须是解密状态. 目前Requests不支持使用加密的 key
|
||||
|
||||
# 流式上传, 允许你发送大的数据流或文件而无需先把它们读入内存
|
||||
with open("massive-body") as f:
|
||||
requests.post("http://some.url/streamed", data=f)
|
||||
|
||||
|
||||
# 事件挂钩, 可用的钩子: response(从一个请求产生的响应)
|
||||
# 你可以通过传递一个 {hook_name: callback_function} 字典给 hooks 请求参数为每个请求分配一个钩子函数
|
||||
def print_url(resp):
|
||||
print(resp.url)
|
||||
return
|
||||
requests.get("http://httpbin.org", hooks=dict(response=print_url))
|
||||
|
||||
# 代理
|
||||
proxies = {
|
||||
"http": "http://10.10.1.10:3128",
|
||||
"https": "http://10.10.1.10:1080",
|
||||
}
|
||||
requests.get("http://example.org", proxies=proxies)
|
||||
# 若代理需要使用HTTP Basic Auth, 可以使用http://user:password@host:port/, 比如"http": "http://user:pass@10.10.1.10:3128/"
|
||||
|
||||
# 除了基本的 HTTP 代理, Request 还支持 SOCKS 协议的代理
|
||||
# $ pip install requests[socks]
|
||||
proxies = {
|
||||
"http": "socks5://user:pass@host:port",
|
||||
"https": "socks5://user:pass@host:port"
|
||||
}
|
||||
requests.get("http://example.org", proxies=proxies)
|
||||
Loading…
Reference in New Issue