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requests/docs/user/quickstart.rst
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Kenneth Reitz 1bc377b188 r.text
2012-01-23 02:42:34 -05:00

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.. _quickstart:
Quickstart
==========
.. module:: requests.models
Eager to get started? This page gives a good introduction in how to get started
with Requests. This assumes you already have Requests installed. If you do not,
head over to the :ref:`Installation <install>` section.
First, make sure that:
* Requests is :ref:`installed <install>`
* Requests is :ref:`up-to-date <updates>`
Lets gets started with some simple use cases and examples.
Make a GET Request
------------------
Making a standard request with Requests is very simple.
Let's get GitHub's public timeline ::
r = requests.get('https://github.com/timeline.json')
Now, we have a :class:`Response` object called ``r``. We can get all the
information we need from this.
Response Content
----------------
We can read the content of the server's response::
>>> r.text
'[{"repository":{"open_issues":0,"url":"https://github.com/...
Requests will automatically decode content from the server. Most unicode
charsets are seamlessly decoded.
When you make a request, ``r.encoding`` is set, based on the HTTP headers.
Requests will use that encoding when you access ``r.text``. If ``r.encoding``
is ``None``, Requests will make an extremely educated guess of the encoding
of the response body. You can manually set ``r.encoding`` to any encoding
you'd like, and that charset will be used.
Binary Response Content
-----------------------
You can also access the response body as bytes, for non-text requests::
>>> r.content
b'[{"repository":{"open_issues":0,"url":"https://github.com/...
The ``gzip`` and ``deflate`` transfer-encodings are automatically decoded for you.
Raw Response Content
--------------------
In the rare case that you'd like to get the absolute raw socket response from the server,
you can access ``r.raw``::
>>> r.raw
<requests.packages.urllib3.response.HTTPResponse object at 0x101194810>
>>> r.raw.read(10)
'\x1f\x8b\x08\x00\x00\x00\x00\x00\x00\x03'
Make a POST Request
-------------------
POST requests are equally simple::
r = requests.post("http://httpbin.org/post")
Typically, you want to send some form-encoded data — much like an HTML form.
To do this, simply pass a dictionary to the `data` argument. Your
dictionary of data will automatically be form-encoded when the request is made::
>>> payload = {'key1': 'value1', 'key2': 'value2'}
>>> r = requests.post("http://httpbin.org/post", data=payload)
>>> print r.text
{
"origin": "179.13.100.4",
"files": {},
"form": {
"key2": "value2",
"key1": "value1"
},
"url": "http://httpbin.org/post",
"args": {},
"headers": {
"Content-Length": "23",
"Accept-Encoding": "identity, deflate, compress, gzip",
"Accept": "*/*",
"User-Agent": "python-requests/0.8.0",
"Host": "127.0.0.1:7077",
"Content-Type": "application/x-www-form-urlencoded"
},
"data": ""
}
There are many times that you want to send data that is not form-encoded. If you pass in a ``string`` instead of a ``dict``, that data will be posted directly.
For example, the GitHub API v3 accepts JSON-Encoded POST/PATCH data::
url = 'https://api.github.com/some/endpoint'
payload = {'some': 'data'}
r = requests.post(url, data=json.dumps(payload))
Custom Headers
--------------
If you'd like to add HTTP headers to a request, simply pass in a ``dict`` to the
``headers`` parameter.
For example, we didn't specify our content-type in the previous example::
url = 'https://api.github.com/some/endpoint'
payload = {'some': 'data'}
headers = {'content-type': 'application/json'}
r = requests.post(url, data=json.dumps(payload), headers=headers)
POST a Multipart-Encoded File
-----------------------------
Requests makes it simple to upload Multipart-encoded files::
>>> url = 'http://httpbin.org/post'
>>> files = {'report.xls': open('report.xls', 'rb')}
>>> r = requests.post(url, files=files)
>>> r.text
{
"origin": "179.13.100.4",
"files": {
"report.xls": "<censored...binary...data>"
},
"form": {},
"url": "http://httpbin.org/post",
"args": {},
"headers": {
"Content-Length": "3196",
"Accept-Encoding": "identity, deflate, compress, gzip",
"Accept": "*/*",
"User-Agent": "python-requests/0.8.0",
"Host": "httpbin.org:80",
"Content-Type": "multipart/form-data; boundary=127.0.0.1.502.21746.1321131593.786.1"
},
"data": ""
}
Setting filename explicitly::
>>> url = 'http://httpbin.org/post'
>>> files = {'file': ('report.xls', open('report.xls', 'rb'))}
>>> r = requests.post(url, files=files)
>>> r.text
{
"origin": "179.13.100.4",
"files": {
"file": "<censored...binary...data>"
},
"form": {},
"url": "http://httpbin.org/post",
"args": {},
"headers": {
"Content-Length": "3196",
"Accept-Encoding": "identity, deflate, compress, gzip",
"Accept": "*/*",
"User-Agent": "python-requests/0.8.0",
"Host": "httpbin.org:80",
"Content-Type": "multipart/form-data; boundary=127.0.0.1.502.21746.1321131593.786.1"
},
"data": ""
}
Response Status Codes
---------------------
We can check the response status code::
>>> r.status_code
200
Requests also comes with a built-in status code lookup object for easy
reference::
>>> r.status_code == requests.codes.ok
True
If we made a bad request (non-200 response), we can raise it with
:class:`Response.raise_for_status()`::
>>> _r = requests.get('http://httpbin.org/status/404')
>>> _r.status_code
404
>>> _r.raise_for_status()
Traceback (most recent call last):
File "requests/models.py", line 394, in raise_for_status
raise self.error
urllib2.HTTPError: HTTP Error 404: NOT FOUND
But, since our ``status_code`` was ``200``, when we call it::
>>> r.raise_for_status()
None
All is well.
Response Headers
----------------
We can view the server's response headers with a simple Python dictionary
interface::
>>> r.headers
{
'status': '200 OK',
'content-encoding': 'gzip',
'transfer-encoding': 'chunked',
'connection': 'close',
'server': 'nginx/1.0.4',
'x-runtime': '148ms',
'etag': '"e1ca502697e5c9317743dc078f67693f"',
'content-type': 'application/json; charset=utf-8'
}
The dictionary is special, though: it's made just for HTTP headers. According to
`RFC 2616 <http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html>`_, HTTP
Headers are case-insensitive.
So, we can access the headers using any capitalization we want::
>>> r.headers['Content-Type']
'application/json; charset=utf-8'
>>> r.headers.get('content-type')
'application/json; charset=utf-8'
If a header doesn't exist in the Response, its value defaults to ``None``::
>>> r.headers['X-Random']
None
Cookies
-------
If a response contains some Cookies, you can get quick access to them::
>>> url = 'http://httpbin.org/cookies/set/requests-is/awesome'
>>> r = requests.get(url)
>>> print r.cookies
{'requests-is': 'awesome'}
To send your own cookies to the server, you can use the ``cookies``
parameter::
>>> url = 'http://httpbin.org/cookies'
>>> cookies = dict(cookies_are='working')
>>> r = requests.get(url, cookies=cookies)
>>> r.text
'{"cookies": {"cookies_are": "working"}}'
Basic Authentication
--------------------
Most web services require authentication. There many different types of
authentication, but the most common is HTTP Basic Auth.
Making requests with Basic Auth is extremely simple::
>>> from requests.auth import HTTPBasicAuth
>>> requests.get('https://api.github.com/user', auth=HTTPBasicAuth('user', 'pass'))
<Response [200]>
Due to the prevalence of HTTP Basic Auth, requests provides a shorthand for
this authentication method::
>>> requests.get('https://api.github.com/user', auth=('user', 'pass'))
<Response [200]>
Providing the credentials as a tuple in this fashion is functionally equivalent
to the ``HTTPBasicAuth`` example above.
Digest Authentication
---------------------
Another popular form of web service protection is Digest Authentication::
>>> from requests.auth import HTTPDigestAuth
>>> url = 'http://httpbin.org/digest-auth/auth/user/pass'
>>> requests.get(url, auth=HTTPDigestAuth('user', 'pass'))
<Response [200]>
OAuth Authentication
--------------------
Miguel Araujo's `requests-oauth <http://pypi.python.org/pypi/requests-oauth>`_ project provides a simple interface for
establishing OAuth connections. Documentation and examples can be found on the requests-oauth `git repository <https://github.com/maraujop/requests-oauth>`_.
Redirection and History
-----------------------
Requests will automatically perform location redirection while using idempotent methods.
GitHub redirects all HTTP requests to HTTPS. Let's see what happens::
>>> r = requests.get('http://github.com')
>>> r.url
'https://github.com/'
>>> r.status_code
200
>>> r.history
[<Response [301]>]
The :class:`Response.history` list contains a list of the
:class:`Request` objects that were created in order to complete the request.
If you're using GET, HEAD, or OPTIONS, you can disable redirection
handling with the ``allow_redirects`` parameter::
>>> r = requests.get('http://github.com', allow_redirects=False)
>>> r.status_code
301
>>> r.history
[]
If you're using POST, PUT, PATCH, *&c*, you can also explicitly enable redirection as well::
>>> r = requests.post('http://github.com', allow_redirects=True)
>>> r.url
'https://github.com/'
>>> r.history
[<Response [301]>]
Timeouts
--------
You can tell requests to stop waiting for a response after a given number of seconds with the ``timeout`` parameter::
>>> requests.get('http://github.com', timeout=0.001)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
requests.exceptions.Timeout: Request timed out.
.. admonition:: Note
``timeout`` only effects the connection process itself, not the downloading of the response body.
Errors and Exceptions
---------------------
In the event of a network problem (e.g. DNS failure, refused connection, etc),
Requests will raise a :class:`ConnectionError` exception.
In the event of the rare invalid HTTP response, Requests will raise
an :class:`HTTPError` exception.
If a request times out, a :class:`Timeout` exception is raised.
If a request exceeds the configured number of maximum redirections, a :class:`TooManyRedirects` exception is raised.
All exceptions that Requests explicitly raises inherit from
:class:`requests.exceptions.RequestException`.
You can refer to :ref:`Configuration API Docs <configurations>` for immediate raising of :class:`HTTPError` exceptions
via the ``danger_mode`` option or have Requests catch the majority of :class:`requests.exceptions.RequestException` exceptions
with the ``safe_mode`` option.
-----------------------
Ready for more? Check out the :ref:`advanced <advanced>` section.