"""Stateful programmatic WWW navigation, after Perl's WWW::Mechanize.
Copyright 2003-2006 John J. Lee <jjl@pobox.com>
Copyright 2003 Andy Lester (original Perl code)
This code is free software; you can redistribute it and/or modify it
under the terms of the BSD or ZPL 2.1 licenses (see the file LICENSE
included with the distribution).
"""
from __future__ import absolute_import
import copy
import os
import re
from . import _request, _response, _rfc3986, _sockettimeout, _urllib2_fork
from ._clientcookie import Cookie
from ._headersutil import normalize_header_name
from ._html import Factory
from ._useragent import UserAgentBase
from .polyglot import pathname2url, HTTPError, is_string, iteritems
from ._response import make_response
class BrowserStateError(Exception):
pass
class LinkNotFoundError(Exception):
pass
class FormNotFoundError(Exception):
pass
def sanepathname2url(path):
urlpath = pathname2url(path)
if os.name == "nt" and urlpath.startswith("///"):
urlpath = urlpath[2:]
# XXX don't ask me about the mac...
return urlpath
[docs]class History:
"""
Though this will become public, the implied interface is not yet stable.
"""
def __init__(self):
self._history = [] # LIFO
def add(self, request, response):
self._history.append((request, response))
def back(self, n, _response):
response = _response # XXX move Browser._response into this class?
while n > 0 or response is None:
try:
request, response = self._history.pop()
except IndexError:
raise BrowserStateError("already at start of history")
n -= 1
return request, response
def clear(self):
del self._history[:]
def close(self):
for request, response in self._history:
if response is not None:
response.close()
del self._history[:]
def __copy__(self):
ans = self.__class__()
ans._history = self._history[:]
return ans
class HTTPRefererProcessor(_urllib2_fork.BaseHandler):
def http_request(self, request):
# See RFC 2616 14.36. The only times we know the source of the
# request URI has a URI associated with it are redirect, and
# Browser.click() / Browser.submit() / Browser.follow_link().
# Otherwise, it's the user's job to add any Referer header before
# .open()ing.
if hasattr(request, "redirect_dict"):
request = self.parent._add_referer_header(
request, origin_request=False)
return request
https_request = http_request
[docs]class Browser(UserAgentBase):
"""Browser-like class with support for history, forms and links.
:class:`BrowserStateError` is raised whenever the browser is in the wrong
state to complete the requested operation - e.g., when :meth:`back()` is
called when the browser history is empty, or when :meth:`follow_link()` is
called when the current response does not contain HTML data.
Public attributes:
request: current request (:class:`mechanize.Request`)
form: currently selected form (see :meth:`select_form()`)
:param history: object implementing the :class:`mechanize.History`
interface. Note this interface is still experimental
and may change in future. This object is owned
by the browser instance and must not be shared
among browsers.
:param request_class: Request class to use. Defaults to
:class:`mechanize.Request`
:param content_parser: A function that is responsible for parsing
received html/xhtml content. See the builtin
:func:`mechanize._html.content_parser()` function for details
on the interface this function must support.
:param factory_class: HTML Factory class to use. Defaults to
:class:`mechanize.Factory`
"""
handler_classes = copy.copy(UserAgentBase.handler_classes)
handler_classes["_referer"] = HTTPRefererProcessor
default_features = copy.copy(UserAgentBase.default_features)
default_features.append("_referer")
def __init__(
self,
history=None,
request_class=None,
content_parser=None,
factory_class=Factory,
allow_xhtml=False, ):
"""
Only named arguments should be passed to this constructor.
"""
self._handle_referer = True
if history is None:
history = History()
self._history = history
if request_class is None:
request_class = _request.Request
factory = factory_class(allow_xhtml=allow_xhtml)
factory.set_request_class(request_class)
if content_parser is not None:
factory.set_content_parser(content_parser)
self._factory = factory
self.request_class = request_class
self.request = None
self._set_response(None, False)
# do this last to avoid __getattr__ problems
UserAgentBase.__init__(self)
def __copy__(self):
'''
Clone this browser instance. The clone will share the same, thread-safe
cookie jar, and have all the same handlers/settings, but will not share
any other state, making it safe to use in another thread.
'''
ans = self.__class__()
self._copy_state(ans)
ans._handle_referer = self._handle_referer
for attr in ('_response_type_finder', '_encoding_finder',
'_content_parser'):
setattr(ans._factory, attr, getattr(self._factory, attr))
ans.request_class = self.request_class
ans._history = copy.copy(self._history)
return ans
def close(self):
UserAgentBase.close(self)
if self._response is not None:
self._response.close()
if self._history is not None:
self._history.close()
self._history = None
# make use after .close easy to spot
self.form = None
self.request = self._response = None
self.request = self.response = self.set_response = None
self.geturl = self.reload = self.back = None
self.clear_history = self.set_cookie = self.links = self.forms = None
self.viewing_html = self.encoding = self.title = None
self.select_form = self.click = self.submit = self.click_link = None
self.follow_link = self.find_link = None
[docs] def set_handle_referer(self, handle):
"""Set whether to add Referer header to each request."""
self._set_handler("_referer", handle)
self._handle_referer = bool(handle)
def _add_referer_header(self, request, origin_request=True):
if self.request is None:
return request
scheme = request.get_type()
original_scheme = self.request.get_type()
if scheme not in ["http", "https"]:
return request
if not origin_request and not self.request.has_header("Referer"):
return request
if (self._handle_referer and original_scheme in ["http", "https"] and
not (original_scheme == "https" and scheme != "https")):
# strip URL fragment (RFC 2616 14.36)
parts = _rfc3986.urlsplit(self.request.get_full_url())
parts = parts[:-1] + (None, )
referer = _rfc3986.urlunsplit(parts)
request.add_unredirected_header("Referer", referer)
return request
[docs] def open_novisit(self,
url_or_request,
data=None,
timeout=_sockettimeout._GLOBAL_DEFAULT_TIMEOUT):
"""Open a URL without visiting it.
Browser state (including request, response, history, forms and links)
is left unchanged by calling this function.
The interface is the same as for :meth:`open()`.
This is useful for things like fetching images.
See also :meth:`retrieve()`
"""
return self._mech_open(
url_or_request, data, visit=False, timeout=timeout)
[docs] def open(self,
url_or_request,
data=None,
timeout=_sockettimeout._GLOBAL_DEFAULT_TIMEOUT):
'''
Open a URL. Loads the page so that you can subsequently use
:meth:`forms()`, :meth:`links()`, etc. on it.
:param url_or_request: Either a URL or a :class:`mechanize.Request`
:param dict data: data to send with a POST request
:param timeout: Timeout in seconds
:return: A :class:`mechanize.Response` object
'''
return self._mech_open(url_or_request, data, timeout=timeout)
def _mech_open(self,
url,
data=None,
update_history=True,
visit=None,
timeout=_sockettimeout._GLOBAL_DEFAULT_TIMEOUT):
try:
url.get_full_url
except AttributeError:
# string URL -- convert to absolute URL if required
scheme, authority = _rfc3986.urlsplit(url)[:2]
if scheme is None:
# relative URL
if self._response is None:
raise BrowserStateError("can't fetch relative reference: "
"not viewing any document")
url = _rfc3986.urljoin(self._response.geturl(), url)
request = self._request(url, data, visit, timeout)
visit = request.visit
if visit is None:
visit = True
if visit:
self._visit_request(request, update_history)
success = True
try:
response = UserAgentBase.open(self, request, data)
except HTTPError as error:
success = False
if error.fp is None: # not a response
raise
response = error
# except (IOError, socket.error, OSError) as error:
# Yes, urllib2 really does raise all these :-((
# See test_urllib2.py for examples of socket.gaierror and OSError,
# plus note that FTPHandler raises IOError.
# XXX I don't seem to have an example of exactly socket.error being
# raised, only socket.gaierror...
# I don't want to start fixing these here, though, since this is a
# subclass of OpenerDirector, and it would break old code. Even in
# Python core, a fix would need some backwards-compat. hack to be
# acceptable.
# raise
if visit:
self._set_response(response, False)
response = copy.copy(self._response)
elif response is not None:
response = _response.upgrade_response(response)
if not success:
raise response
return response
def __str__(self):
text = []
text.append("<%s " % self.__class__.__name__)
if self._response:
text.append("visiting %s" % self._response.geturl())
else:
text.append("(not visiting a URL)")
if self.form:
text.append("\n selected form:\n %s\n" % str(self.form))
text.append(">")
return "".join(text)
[docs] def response(self):
"""Return a copy of the current response.
The returned object has the same interface as the object returned by
:meth:`.open()`
"""
return copy.copy(self._response)
def open_local_file(self, filename):
path = sanepathname2url(os.path.abspath(filename))
url = 'file://' + path
return self.open(url)
[docs] def set_response(self, response):
"""Replace current response with (a copy of) response.
response may be None.
This is intended mostly for HTML-preprocessing.
"""
self._set_response(response, True)
def _set_response(self, response, close_current):
# sanity check, necessary but far from sufficient
if not (response is None or
(hasattr(response, "info") and hasattr(response, "geturl") and
hasattr(response, "read"))):
raise ValueError("not a response object")
self.form = None
if response is not None:
response = _response.upgrade_response(response)
if close_current and self._response is not None:
self._response.close()
self._response = response
self._factory.set_response(response)
[docs] def visit_response(self, response, request=None):
"""Visit the response, as if it had been :meth:`open()` ed.
Unlike :meth:`set_response()`, this updates history rather than
replacing the current response.
"""
if request is None:
request = _request.Request(response.geturl())
self._visit_request(request, True)
self._set_response(response, False)
def _visit_request(self, request, update_history):
if self._response is not None:
self._response.close()
if self.request is not None and update_history:
self._history.add(self.request, self._response)
self._response = None
# we want self.request to be assigned even if UserAgentBase.open
# fails
self.request = request
[docs] def set_html(self, html, url="http://example.com/"):
"""Set the response to dummy with given HTML, and URL if given.
Allows you to then parse that HTML, especially to extract forms
information. If no URL was given then the default is "example.com".
"""
response = make_response(html, [("Content-type", "text/html")], url)
self._set_response(response, True)
[docs] def geturl(self):
"""Get URL of current document."""
if self._response is None:
raise BrowserStateError("not viewing any document")
return self._response.geturl()
[docs] def reload(self):
"""Reload current document, and return response object."""
if self.request is None:
raise BrowserStateError("no URL has yet been .open()ed")
if self._response is not None:
self._response.close()
return self._mech_open(self.request, update_history=False)
[docs] def back(self, n=1):
"""Go back n steps in history, and return response object.
n: go back this number of steps (default 1 step)
"""
if self._response is not None:
self._response.close()
self.request, response = self._history.back(n, self._response)
self.set_response(response)
if not response.read_complete:
return self.reload()
return copy.copy(response)
def clear_history(self):
self._history.clear()
[docs] def set_cookie(self, cookie_string):
"""Set a cookie.
Note that it is NOT necessary to call this method under ordinary
circumstances: cookie handling is normally entirely automatic. The
intended use case is rather to simulate the setting of a cookie by
client script in a web page (e.g. JavaScript). In that case, use of
this method is necessary because mechanize currently does not support
JavaScript, VBScript, etc.
The cookie is added in the same way as if it had arrived with the
current response, as a result of the current request. This means that,
for example, if it is not appropriate to set the cookie based on the
current request, no cookie will be set.
The cookie will be returned automatically with subsequent responses
made by the Browser instance whenever that's appropriate.
cookie_string should be a valid value of the Set-Cookie header.
For example:
.. code-block:: python
browser.set_cookie(
"sid=abcdef; expires=Wednesday, 09-Nov-06 23:12:40 GMT")
Currently, this method does not allow for adding RFC 2986 cookies.
This limitation will be lifted if anybody requests it.
See also :meth:`set_simple_cookie()` for an easier way to set cookies
without needing to create a Set-Cookie header string.
"""
if self._response is None:
raise BrowserStateError("not viewing any document")
if self.request.get_type() not in ["http", "https"]:
raise BrowserStateError("can't set cookie for non-HTTP/HTTPS "
"transactions")
cookiejar = self._ua_handlers["_cookies"].cookiejar
response = self.response() # copy
headers = response.info()
headers["Set-cookie"] = cookie_string
cookiejar.extract_cookies(response, self.request)
[docs] def set_simple_cookie(self, name, value, domain, path='/'):
'''
Similar to :meth:`set_cookie()` except that instead of using a
cookie string, you simply specify the `name`, `value`, `domain`
and optionally the `path`.
The created cookie will never expire. For example:
.. code-block:: python
browser.set_simple_cookie('some_key', 'some_value', '.example.com',
path='/some-page')
'''
self.cookiejar.set_cookie(
Cookie(0, name, value, None, False, domain, True, False, path,
True, False, None, False, None, None, None))
@property
def cookiejar(self):
' Return the current cookiejar (:class:`mechanize.CookieJar`) or None '
try:
return self._ua_handlers["_cookies"].cookiejar
except Exception:
pass
[docs] def links(self, **kwds):
"""Return iterable over links (:class:`mechanize.Link` objects)."""
if not self.viewing_html():
raise BrowserStateError("not viewing HTML")
links = self._factory.links()
if kwds:
return self._filter_links(links, **kwds)
else:
return links
[docs] def viewing_html(self):
"""Return whether the current response contains HTML data."""
if self._response is None:
raise BrowserStateError("not viewing any document")
return self._factory.is_html
def encoding(self):
if self._response is None:
raise BrowserStateError("not viewing any document")
return self._factory.encoding
[docs] def title(self):
' Return title, or None if there is no title element in the document. '
if not self.viewing_html():
raise BrowserStateError("not viewing HTML")
return self._factory.title
[docs] def click(self, *args, **kwds):
"""See :meth:`mechanize.HTMLForm.click()` for documentation."""
if not self.viewing_html():
raise BrowserStateError("not viewing HTML")
request = self.form.click(*args, **kwds)
return self._add_referer_header(request)
[docs] def submit(self, *args, **kwds):
"""Submit current form.
Arguments are as for :meth:`mechanize.HTMLForm.click()`.
Return value is same as for :meth:`open()`.
"""
return self.open(self.click(*args, **kwds))
[docs] def click_link(self, link=None, **kwds):
"""Find a link and return a Request object for it.
Arguments are as for :meth:`find_link()`, except that a link may be
supplied as the first argument.
"""
if not self.viewing_html():
raise BrowserStateError("not viewing HTML")
if not link:
link = self.find_link(**kwds)
else:
if kwds:
raise ValueError(
"either pass a Link, or keyword arguments, not both")
request = self.request_class(link.absolute_url)
return self._add_referer_header(request)
[docs] def follow_link(self, link=None, **kwds):
"""Find a link and :meth:`open()` it.
Arguments are as for :meth:`click_link()`.
Return value is same as for :meth:`open()`.
"""
return self.open(self.click_link(link, **kwds))
[docs] def find_link(self,
text=None,
text_regex=None,
name=None,
name_regex=None,
url=None,
url_regex=None,
tag=None,
predicate=None,
nr=0):
"""Find a link in current page.
Links are returned as :class:`mechanize.Link` objects. Examples:
.. code-block:: python
# Return third link that .search()-matches the regexp "python" (by
# ".search()-matches", I mean that the regular expression method
# .search() is used, rather than .match()).
find_link(text_regex=re.compile("python"), nr=2)
# Return first http link in the current page that points to
# somewhere on python.org whose link text (after tags have been
# removed) is exactly "monty python".
find_link(text="monty python",
url_regex=re.compile("http.*python.org"))
# Return first link with exactly three HTML attributes.
find_link(predicate=lambda link: len(link.attrs) == 3)
Links include anchors `<a>`, image maps `<area>`, and frames
`<iframe>`.
All arguments must be passed by keyword, not position. Zero or more
arguments may be supplied. In order to find a link, all arguments
supplied must match.
If a matching link is not found, :class:`mechanize.LinkNotFoundError`
is raised.
:param text: link text between link tags: e.g. <a href="blah">this
bit</a> with whitespace compressed.
:param text_regex: link text between tag (as defined above) must match
the regular expression object or regular expression string passed
as this argument, if supplied
:param name: as for text and text_regex, but matched
against the name HTML attribute of the link tag
:param url: as for text and text_regex, but matched against the
URL of the link tag (note this matches against Link.url, which is a
relative or absolute URL according to how it was written in the
HTML)
:param tag: element name of opening tag, e.g. "a"
:param predicate: a function taking a Link object as its single
argument, returning a boolean result, indicating whether the links
:param nr: matches the nth link that matches all other
criteria (default 0)
"""
try:
return next(self._filter_links(
self._factory.links(), text, text_regex, name, name_regex, url,
url_regex, tag, predicate, nr))
except StopIteration:
raise LinkNotFoundError()
def __getattr__(self, name):
# pass through _form.HTMLForm methods and attributes
form = self.__dict__.get("form")
if form is None:
raise AttributeError(
"%s instance has no attribute %s (perhaps you forgot to "
".select_form()?)" % (self.__class__, name))
return getattr(form, name)
def __getitem__(self, name):
if self.form is None:
raise BrowserStateError('No form selected')
return self.form[name]
def __setitem__(self, name, val):
if self.form is None:
raise BrowserStateError('No form selected')
self.form[name] = val
def _filter_links(self,
links,
text=None,
text_regex=None,
name=None,
name_regex=None,
url=None,
url_regex=None,
tag=None,
predicate=None,
nr=0):
if not self.viewing_html():
raise BrowserStateError("not viewing HTML")
orig_nr = nr
for link in links:
if url is not None and url != link.url:
continue
if url_regex is not None and not re.search(url_regex, link.url):
continue
if (text is not None and (link.text is None or text != link.text)):
continue
if (
text_regex is not None and (
link.text is None or not re.search(
text_regex, link.text))):
continue
if name is not None and name != dict(link.attrs).get("name"):
continue
if name_regex is not None:
link_name = dict(link.attrs).get("name")
if link_name is None or not re.search(name_regex, link_name):
continue
if tag is not None and tag != link.tag:
continue
if predicate is not None and not predicate(link):
continue
if nr:
nr -= 1
continue
yield link
nr = orig_nr