Day6-requests.get

第 11 屆 iThome 鐵人賽

DAY 6

自我挑戰組

Why it works: python requests and urllib3系列第 6 篇

11th鐵人賽 why it works

j2hongming

2019-09-22 22:53:45

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Why requests.get works

來看看README內的給我們的範例

import requests
r = requests.get('https://api.github.com/user', auth=('user', 'pass'))
r.status_code

Why requests.get works?

到目前為止的理解是因為兩個因素

When a regular package is imported, this __init__.py file is implicitly executed
requests的__init__.py內的宣告

from .api import request, get, head, post, patch, put, delete, options

感覺起來，可以把對外的使用介面，例如: get, post, session...等宣告在__init__.py內，方便其他引用該package的人使用。

requests.api module

定義了HTTP Method: get, options, head, post, put, patch, delete

def get(url, params=None, **kwargs):
    r"""Sends a GET request.
    :param url: URL for the new :class:`Request` object.
    :param params: (optional) Dictionary, list of tuples or bytes to send
        in the query string for the :class:`Request`.
    :param \*\*kwargs: Optional arguments that ``request`` takes.
    :return: :class:`Response <Response>` object
    :rtype: requests.Response
    """

    kwargs.setdefault('allow_redirects', True)
    return request('get', url, params=params, **kwargs)

說明包含:param, :return, :rtype
可以知道requests核心有兩個主要的物件: Request, Response
在文件中看起來的呈現

但其實這7個function都是wrapper function，最後都會使用的function是request。
核心是sessions模組內的Session物件

def request(method, ur, **kwargs):
    # By using the 'with' statement we are sure the session is closed, thus we
    # avoid leaving sockets open which can trigger a ResourceWarning in some
    # cases, and look like a memory leak in others.
    with sessions.Session() as session:
        return session.request(method=method, url=url, **kwargs)

可以帶入的參數種類非常多，整理docstring的內容如下

	HTTP	docstrings
params	query string	(optional) Dictionary, list of tuples or bytes to send in the query string for the :class:`Request`.
data	body	(optional) Dictionary, list of tuples, bytes, or file-like object to send in the body of the :class:`Request`.
json	body	(optional) A JSON serializable Python object to send in the body of the :class:`Request`.
headers	Headers	(optional) Dictionary of HTTP Headers to send with the :class:`Request`.
cookies		(optional) Dict or CookieJar object to send with the :class:`Request`.
files		(optional) Dictionary of `'name': file-like-objects` (or `{'name': file-tuple}`) for multipart encoding upload.`file-tuple` can be a 2-tuple `('filename', fileobj)`, 3-tuple `('filename', fileobj, 'content_type')` or a 4-tuple `('filename', fileobj, 'content_type', custom_headers)`, where `'content-type'` is a string defining the content type of the given file and `custom_headers` a dict-like object containing additional headers to add for the file.
auth	Headers	(optional) Auth tuple to enable Basic/Digest/Custom HTTP Auth.
timeout		(optional) How many seconds to wait for the server to send data before giving up, as a float, or a :ref:`(connect timeout, read timeout) <timeouts>` tuple.
allow_redirects		(optional) Boolean. Enable/disable GET/OPTIONS/POST/PUT/PATCH/DELETE/HEAD redirection. Defaults to `True`.
proxies		(optional) Dictionary mapping protocol to the URL of the proxy.
verify		(optional) Either a boolean, in which case it controls whether we verify the server's TLS certificate, or a string, in which case it must be a path to a CA bundle to use. Defaults to `True`.
stream		(optional) if `False`, the response content will be immediately downloaded.
cert		(optional) if String, path to ssl client cert file (.pem). If Tuple, ('cert', 'key') pair.