urllib.request — Extensible library for opening URLs (original) (raw)

Source code: Lib/urllib/request.py

The urllib.request module defines functions and classes which help in opening URLs (mostly HTTP) in a complex world — basic and digest authentication, redirections, cookies and more.

See also

The Requests packageis recommended for a higher-level HTTP client interface.

Warning

On macOS it is unsafe to use this module in programs usingos.fork() because the getproxies() implementation for macOS uses a higher-level system API. Set the environment variableno_proxy to * to avoid this problem (e.g. os.environ["no_proxy"] = "*").

The urllib.request module defines the following functions:

urllib.request.urlopen(url, data=None, [timeout, ]*, context=None)

Open url, which can be either a string containing a valid, properly encoded URL, or a Request object.

data must be an object specifying additional data to be sent to the server, or None if no such data is needed. See Requestfor details.

urllib.request module uses HTTP/1.1 and includes Connection:close header in its HTTP requests.

The optional timeout parameter specifies a timeout in seconds for blocking operations like the connection attempt (if not specified, the global default timeout setting will be used). This actually only works for HTTP, HTTPS and FTP connections.

If context is specified, it must be a ssl.SSLContext instance describing the various SSL options. See HTTPSConnectionfor more details.

This function always returns an object which can work as acontext manager and has the properties url, headers, and status. See urllib.response.addinfourl for more detail on these properties.

For HTTP and HTTPS URLs, this function returns ahttp.client.HTTPResponse object slightly modified. In addition to the three new methods above, the msg attribute contains the same information as the reasonattribute — the reason phrase returned by server — instead of the response headers as it is specified in the documentation forHTTPResponse.

For FTP, file, and data URLs and requests explicitly handled by legacyURLopener and FancyURLopener classes, this function returns a urllib.response.addinfourl object.

Raises URLError on protocol errors.

Note that None may be returned if no handler handles the request (though the default installed global OpenerDirector usesUnknownHandler to ensure this never happens).

In addition, if proxy settings are detected (for example, when a *_proxyenvironment variable like http_proxy is set),ProxyHandler is default installed and makes sure the requests are handled through the proxy.

The legacy urllib.urlopen function from Python 2.6 and earlier has been discontinued; urllib.request.urlopen() corresponds to the oldurllib2.urlopen. Proxy handling, which was done by passing a dictionary parameter to urllib.urlopen, can be obtained by usingProxyHandler objects.

The default opener raises an auditing event urllib.Request with arguments fullurl, data, headers,method taken from the request object.

Changed in version 3.2: cafile and capath were added.

HTTPS virtual hosts are now supported if possible (that is, ifssl.HAS_SNI is true).

data can be an iterable object.

Changed in version 3.3: cadefault was added.

Changed in version 3.4.3: context was added.

Changed in version 3.10: HTTPS connection now send an ALPN extension with protocol indicatorhttp/1.1 when no context is given. Custom context should set ALPN protocols with set_alpn_protocols().

Changed in version 3.13: Remove cafile, capath and cadefault parameters: use the _context_parameter instead.

urllib.request.install_opener(opener)

Install an OpenerDirector instance as the default global opener. Installing an opener is only necessary if you want urlopen to use that opener; otherwise, simply call OpenerDirector.open() instead ofurlopen(). The code does not check for a realOpenerDirector, and any class with the appropriate interface will work.

urllib.request.build_opener([handler, _..._])

Return an OpenerDirector instance, which chains the handlers in the order given. _handler_s can be either instances of BaseHandler, or subclasses of BaseHandler (in which case it must be possible to call the constructor without any parameters). Instances of the following classes will be in front of the _handler_s, unless the _handler_s contain them, instances of them or subclasses of them: ProxyHandler (if proxy settings are detected), UnknownHandler, HTTPHandler,HTTPDefaultErrorHandler, HTTPRedirectHandler,FTPHandler, FileHandler, HTTPErrorProcessor.

If the Python installation has SSL support (i.e., if the ssl module can be imported), HTTPSHandler will also be added.

A BaseHandler subclass may also change its handler_orderattribute to modify its position in the handlers list.

urllib.request.pathname2url(path)

Convert the given local path to a file: URL. This function usesquote() function to encode the path. For historical reasons, the return value omits the file: scheme prefix. This example shows the function being used on Windows:

from urllib.request import pathname2url path = 'C:\Program Files' 'file:' + pathname2url(path) 'file:///C:/Program%20Files'

urllib.request.url2pathname(url)

Convert the given file: URL to a local path. This function usesunquote() to decode the URL. For historical reasons, the given value must omit the file: scheme prefix. This example shows the function being used on Windows:

from urllib.request import url2pathname url = 'file:///C:/Program%20Files' url2pathname(url.removeprefix('file:')) 'C:\Program Files'

urllib.request.getproxies()

This helper function returns a dictionary of scheme to proxy server URL mappings. It scans the environment for variables named <scheme>_proxy, in a case insensitive approach, for all operating systems first, and when it cannot find it, looks for proxy information from System Configuration for macOS and Windows Systems Registry for Windows. If both lowercase and uppercase environment variables exist (and disagree), lowercase is preferred.

Note

If the environment variable REQUEST_METHOD is set, which usually indicates your script is running in a CGI environment, the environment variable HTTP_PROXY (uppercase _PROXY) will be ignored. This is because that variable can be injected by a client using the “Proxy:” HTTP header. If you need to use an HTTP proxy in a CGI environment, either useProxyHandler explicitly, or make sure the variable name is in lowercase (or at least the _proxy suffix).

The following classes are provided:

class urllib.request.Request(url, data=None, headers={}, origin_req_host=None, unverifiable=False, method=None)

This class is an abstraction of a URL request.

url should be a string containing a valid, properly encoded URL.

data must be an object specifying additional data to send to the server, or None if no such data is needed. Currently HTTP requests are the only ones that use data. The supported object types include bytes, file-like objects, and iterables of bytes-like objects. If no Content-Length nor Transfer-Encoding header field has been provided, HTTPHandler will set these headers according to the type of data. Content-Length will be used to send bytes objects, while Transfer-Encoding: chunked as specified inRFC 7230, Section 3.3.1 will be used to send files and other iterables.

For an HTTP POST request method, data should be a buffer in the standard application/x-www-form-urlencoded format. Theurllib.parse.urlencode() function takes a mapping or sequence of 2-tuples and returns an ASCII string in this format. It should be encoded to bytes before being used as the data parameter.

headers should be a dictionary, and will be treated as ifadd_header() was called with each key and value as arguments. This is often used to “spoof” the User-Agent header value, which is used by a browser to identify itself – some HTTP servers only allow requests coming from common browsers as opposed to scripts. For example, Mozilla Firefox may identify itself as "Mozilla/5.0 (X11; U; Linux i686) Gecko/20071127 Firefox/2.0.0.11", whileurllib’s default user agent string is"Python-urllib/2.6" (on Python 2.6). All header keys are sent in camel case.

An appropriate Content-Type header should be included if the _data_argument is present. If this header has not been provided and _data_is not None, Content-Type: application/x-www-form-urlencoded will be added as a default.

The next two arguments are only of interest for correct handling of third-party HTTP cookies:

origin_req_host should be the request-host of the origin transaction, as defined by RFC 2965. It defaults tohttp.cookiejar.request_host(self). This is the host name or IP address of the original request that was initiated by the user. For example, if the request is for an image in an HTML document, this should be the request-host of the request for the page containing the image.

unverifiable should indicate whether the request is unverifiable, as defined by RFC 2965. It defaults to False. An unverifiable request is one whose URL the user did not have the option to approve. For example, if the request is for an image in an HTML document, and the user had no option to approve the automatic fetching of the image, this should be true.

method should be a string that indicates the HTTP request method that will be used (e.g. 'HEAD'). If provided, its value is stored in themethod attribute and is used by get_method(). The default is 'GET' if data is None or 'POST' otherwise. Subclasses may indicate a different default method by setting themethod attribute in the class itself.

Note

The request will not work as expected if the data object is unable to deliver its content more than once (e.g. a file or an iterable that can produce the content only once) and the request is retried for HTTP redirects or authentication. The data is sent to the HTTP server right away after the headers. There is no support for a 100-continue expectation in the library.

Changed in version 3.3: Request.method argument is added to the Request class.

Changed in version 3.4: Default Request.method may be indicated at the class level.

Changed in version 3.6: Do not raise an error if the Content-Length has not been provided and data is neither None nor a bytes object. Fall back to use chunked transfer encoding instead.

class urllib.request.OpenerDirector

The OpenerDirector class opens URLs via BaseHandlers chained together. It manages the chaining of handlers, and recovery from errors.

class urllib.request.BaseHandler

This is the base class for all registered handlers — and handles only the simple mechanics of registration.

class urllib.request.HTTPDefaultErrorHandler

A class which defines a default handler for HTTP error responses; all responses are turned into HTTPError exceptions.

class urllib.request.HTTPRedirectHandler

A class to handle redirections.

class urllib.request.HTTPCookieProcessor(cookiejar=None)

A class to handle HTTP Cookies.

class urllib.request.ProxyHandler(proxies=None)

Cause requests to go through a proxy. If proxies is given, it must be a dictionary mapping protocol names to URLs of proxies. The default is to read the list of proxies from the environment variables<protocol>_proxy. If no proxy environment variables are set, then in a Windows environment proxy settings are obtained from the registry’s Internet Settings section, and in a macOS environment proxy information is retrieved from the System Configuration Framework.

To disable autodetected proxy pass an empty dictionary.

The no_proxy environment variable can be used to specify hosts which shouldn’t be reached via proxy; if set, it should be a comma-separated list of hostname suffixes, optionally with :port appended, for examplecern.ch,ncsa.uiuc.edu,some.host:8080.

Note

HTTP_PROXY will be ignored if a variable REQUEST_METHOD is set; see the documentation on getproxies().

class urllib.request.HTTPPasswordMgr

Keep a database of (realm, uri) -> (user, password) mappings.

class urllib.request.HTTPPasswordMgrWithDefaultRealm

Keep a database of (realm, uri) -> (user, password) mappings. A realm ofNone is considered a catch-all realm, which is searched if no other realm fits.

class urllib.request.HTTPPasswordMgrWithPriorAuth

A variant of HTTPPasswordMgrWithDefaultRealm that also has a database of uri -> is_authenticated mappings. Can be used by a BasicAuth handler to determine when to send authentication credentials immediately instead of waiting for a 401 response first.

Added in version 3.5.

class urllib.request.AbstractBasicAuthHandler(password_mgr=None)

This is a mixin class that helps with HTTP authentication, both to the remote host and to a proxy. password_mgr, if given, should be something that is compatible with HTTPPasswordMgr; refer to sectionHTTPPasswordMgr Objects for information on the interface that must be supported. If passwd_mgr also provides is_authenticated andupdate_authenticated methods (seeHTTPPasswordMgrWithPriorAuth Objects), then the handler will use theis_authenticated result for a given URI to determine whether or not to send authentication credentials with the request. If is_authenticatedreturns True for the URI, credentials are sent. If is_authenticatedis False, credentials are not sent, and then if a 401 response is received the request is re-sent with the authentication credentials. If authentication succeeds, update_authenticated is called to setis_authenticated True for the URI, so that subsequent requests to the URI or any of its super-URIs will automatically include the authentication credentials.

Added in version 3.5: Added is_authenticated support.

class urllib.request.HTTPBasicAuthHandler(password_mgr=None)

Handle authentication with the remote host. password_mgr, if given, should be something that is compatible with HTTPPasswordMgr; refer to section HTTPPasswordMgr Objects for information on the interface that must be supported. HTTPBasicAuthHandler will raise a ValueError when presented with a wrong Authentication scheme.

class urllib.request.ProxyBasicAuthHandler(password_mgr=None)

Handle authentication with the proxy. password_mgr, if given, should be something that is compatible with HTTPPasswordMgr; refer to sectionHTTPPasswordMgr Objects for information on the interface that must be supported.

class urllib.request.AbstractDigestAuthHandler(password_mgr=None)

This is a mixin class that helps with HTTP authentication, both to the remote host and to a proxy. password_mgr, if given, should be something that is compatible with HTTPPasswordMgr; refer to sectionHTTPPasswordMgr Objects for information on the interface that must be supported.

class urllib.request.HTTPDigestAuthHandler(password_mgr=None)

Handle authentication with the remote host. password_mgr, if given, should be something that is compatible with HTTPPasswordMgr; refer to section HTTPPasswordMgr Objects for information on the interface that must be supported. When both Digest Authentication Handler and Basic Authentication Handler are both added, Digest Authentication is always tried first. If the Digest Authentication returns a 40x response again, it is sent to Basic Authentication handler to Handle. This Handler method will raise aValueError when presented with an authentication scheme other than Digest or Basic.

Changed in version 3.3: Raise ValueError on unsupported Authentication Scheme.

class urllib.request.ProxyDigestAuthHandler(password_mgr=None)

Handle authentication with the proxy. password_mgr, if given, should be something that is compatible with HTTPPasswordMgr; refer to sectionHTTPPasswordMgr Objects for information on the interface that must be supported.

class urllib.request.HTTPHandler

A class to handle opening of HTTP URLs.

class urllib.request.HTTPSHandler(debuglevel=0, context=None, check_hostname=None)

A class to handle opening of HTTPS URLs. context and _check_hostname_have the same meaning as in http.client.HTTPSConnection.

Changed in version 3.2: context and check_hostname were added.

class urllib.request.FileHandler

Open local files.

class urllib.request.DataHandler

Open data URLs.

Added in version 3.4.

class urllib.request.FTPHandler

Open FTP URLs.

class urllib.request.CacheFTPHandler

Open FTP URLs, keeping a cache of open FTP connections to minimize delays.

class urllib.request.UnknownHandler

A catch-all class to handle unknown URLs.

class urllib.request.HTTPErrorProcessor

Process HTTP error responses.

Request Objects

The following methods describe Request’s public interface, and so all may be overridden in subclasses. It also defines several public attributes that can be used by clients to inspect the parsed request.

Request.full_url

The original URL passed to the constructor.

Changed in version 3.4.

Request.full_url is a property with setter, getter and a deleter. Gettingfull_url returns the original request URL with the fragment, if it was present.

Request.type

The URI scheme.

Request.host

The URI authority, typically a host, but may also contain a port separated by a colon.

Request.origin_req_host

The original host for the request, without port.

Request.selector

The URI path. If the Request uses a proxy, then selector will be the full URL that is passed to the proxy.

Request.data

The entity body for the request, or None if not specified.

Changed in version 3.4: Changing value of Request.data now deletes “Content-Length” header if it was previously set or calculated.

Request.unverifiable

boolean, indicates whether the request is unverifiable as defined by RFC 2965.

Request.method

The HTTP request method to use. By default its value is None, which means that get_method() will do its normal computation of the method to be used. Its value can be set (thus overriding the default computation in get_method()) either by providing a default value by setting it at the class level in a Request subclass, or by passing a value in to the Request constructor via the _method_argument.

Added in version 3.3.

Changed in version 3.4: A default value can now be set in subclasses; previously it could only be set via the constructor argument.

Request.get_method()

Return a string indicating the HTTP request method. IfRequest.method is not None, return its value, otherwise return'GET' if Request.data is None, or 'POST' if it’s not. This is only meaningful for HTTP requests.

Changed in version 3.3: get_method now looks at the value of Request.method.

Add another header to the request. Headers are currently ignored by all handlers except HTTP handlers, where they are added to the list of headers sent to the server. Note that there cannot be more than one header with the same name, and later calls will overwrite previous calls in case the key collides. Currently, this is no loss of HTTP functionality, since all headers which have meaning when used more than once have a (header-specific) way of gaining the same functionality using only one header. Note that headers added using this method are also added to redirected requests.

Add a header that will not be added to a redirected request.

Return whether the instance has the named header (checks both regular and unredirected).

Remove named header from the request instance (both from regular and unredirected headers).

Added in version 3.4.

Request.get_full_url()

Return the URL given in the constructor.

Changed in version 3.4.

Returns Request.full_url

Request.set_proxy(host, type)

Prepare the request by connecting to a proxy server. The host and type will replace those of the instance, and the instance’s selector will be the original URL given in the constructor.

Return the value of the given header. If the header is not present, return the default value.

Return a list of tuples (header_name, header_value) of the Request headers.

Changed in version 3.4: The request methods add_data, has_data, get_data, get_type, get_host, get_selector, get_origin_req_host and is_unverifiable that were deprecated since 3.3 have been removed.

OpenerDirector Objects

OpenerDirector instances have the following methods:

OpenerDirector.add_handler(handler)

handler should be an instance of BaseHandler. The following methods are searched, and added to the possible chains (note that HTTP errors are a special case). Note that, in the following, protocol should be replaced with the actual protocol to handle, for example http_response() would be the HTTP protocol response handler. Also type should be replaced with the actual HTTP code, for example http_error_404() would handle HTTP 404 errors.

OpenerDirector.open(url, _data=None_[, _timeout_])

Open the given url (which can be a request object or a string), optionally passing the given data. Arguments, return values and exceptions raised are the same as those of urlopen() (which simply calls the open()method on the currently installed global OpenerDirector). The optional timeout parameter specifies a timeout in seconds for blocking operations like the connection attempt (if not specified, the global default timeout setting will be used). The timeout feature actually works only for HTTP, HTTPS and FTP connections.

OpenerDirector.error(proto, *args)

Handle an error of the given protocol. This will call the registered error handlers for the given protocol with the given arguments (which are protocol specific). The HTTP protocol is a special case which uses the HTTP response code to determine the specific error handler; refer to the http_error_<type>()methods of the handler classes.

Return values and exceptions raised are the same as those of urlopen().

OpenerDirector objects open URLs in three stages:

The order in which these methods are called within each stage is determined by sorting the handler instances.

  1. Every handler with a method named like <protocol>_request() has that method called to pre-process the request.
  2. Handlers with a method named like <protocol>_open() are called to handle the request. This stage ends when a handler either returns a non-Nonevalue (ie. a response), or raises an exception (usuallyURLError). Exceptions are allowed to propagate.
    In fact, the above algorithm is first tried for methods nameddefault_open(). If all such methods return None, the algorithm is repeated for methods named like <protocol>_open(). If all such methods return None, the algorithm is repeated for methods namedunknown_open().
    Note that the implementation of these methods may involve calls of the parentOpenerDirector instance’s open() anderror() methods.
  3. Every handler with a method named like <protocol>_response() has that method called to post-process the response.

BaseHandler Objects

BaseHandler objects provide a couple of methods that are directly useful, and others that are meant to be used by derived classes. These are intended for direct use:

BaseHandler.add_parent(director)

Add a director as parent.

BaseHandler.close()

Remove any parents.

The following attribute and methods should only be used by classes derived fromBaseHandler.

Note

The convention has been adopted that subclasses defining<protocol>_request() or <protocol>_response() methods are named*Processor; all others are named *Handler.

BaseHandler.parent

A valid OpenerDirector, which can be used to open using a different protocol, or handle errors.

BaseHandler.default_open(req)

This method is not defined in BaseHandler, but subclasses should define it if they want to catch all URLs.

This method, if implemented, will be called by the parentOpenerDirector. It should return a file-like object as described in the return value of the open() method of OpenerDirector, or None. It should raise URLError, unless a truly exceptional thing happens (for example, MemoryError should not be mapped toURLError).

This method will be called before any protocol-specific open method.

BaseHandler._open(req)

This method is not defined in BaseHandler, but subclasses should define it if they want to handle URLs with the given protocol.

This method, if defined, will be called by the parent OpenerDirector. Return values should be the same as for default_open().

BaseHandler.unknown_open(req)

This method is not defined in BaseHandler, but subclasses should define it if they want to catch all URLs with no specific registered handler to open it.

This method, if implemented, will be called by the parent OpenerDirector. Return values should be the same as fordefault_open().

BaseHandler.http_error_default(req, fp, code, msg, hdrs)

This method is not defined in BaseHandler, but subclasses should override it if they intend to provide a catch-all for otherwise unhandled HTTP errors. It will be called automatically by the OpenerDirector getting the error, and should not normally be called in other circumstances.

req will be a Request object, fp will be a file-like object with the HTTP error body, code will be the three-digit code of the error, _msg_will be the user-visible explanation of the code and hdrs will be a mapping object with the headers of the error.

Return values and exceptions raised should be the same as those ofurlopen().

BaseHandler.http_error_(req, fp, code, msg, hdrs)

nnn should be a three-digit HTTP error code. This method is also not defined in BaseHandler, but will be called, if it exists, on an instance of a subclass, when an HTTP error with code nnn occurs.

Subclasses should override this method to handle specific HTTP errors.

Arguments, return values and exceptions raised should be the same as forhttp_error_default().

BaseHandler._request(req)

This method is not defined in BaseHandler, but subclasses should define it if they want to pre-process requests of the given protocol.

This method, if defined, will be called by the parent OpenerDirector.req will be a Request object. The return value should be aRequest object.

BaseHandler._response(req, response)

This method is not defined in BaseHandler, but subclasses should define it if they want to post-process responses of the given protocol.

This method, if defined, will be called by the parent OpenerDirector.req will be a Request object. response will be an object implementing the same interface as the return value of urlopen(). The return value should implement the same interface as the return value ofurlopen().

HTTPRedirectHandler Objects

Note

Some HTTP redirections require action from this module’s client code. If this is the case, HTTPError is raised. See RFC 2616 for details of the precise meanings of the various redirection codes.

An HTTPError exception raised as a security consideration if the HTTPRedirectHandler is presented with a redirected URL which is not an HTTP, HTTPS or FTP URL.

HTTPRedirectHandler.redirect_request(req, fp, code, msg, hdrs, newurl)

Return a Request or None in response to a redirect. This is called by the default implementations of the http_error_30*() methods when a redirection is received from the server. If a redirection should take place, return a new Request to allow http_error_30*() to perform the redirect to newurl. Otherwise, raise HTTPError if no other handler should try to handle this URL, or return None if you can’t but another handler might.

Note

The default implementation of this method does not strictly follow RFC 2616, which says that 301 and 302 responses to POST requests must not be automatically redirected without confirmation by the user. In reality, browsers do allow automatic redirection of these responses, changing the POST to aGET, and the default implementation reproduces this behavior.

HTTPRedirectHandler.http_error_301(req, fp, code, msg, hdrs)

Redirect to the Location: or URI: URL. This method is called by the parent OpenerDirector when getting an HTTP ‘moved permanently’ response.

HTTPRedirectHandler.http_error_302(req, fp, code, msg, hdrs)

The same as http_error_301(), but called for the ‘found’ response.

HTTPRedirectHandler.http_error_303(req, fp, code, msg, hdrs)

The same as http_error_301(), but called for the ‘see other’ response.

HTTPRedirectHandler.http_error_307(req, fp, code, msg, hdrs)

The same as http_error_301(), but called for the ‘temporary redirect’ response. It does not allow changing the request method from POSTto GET.

HTTPRedirectHandler.http_error_308(req, fp, code, msg, hdrs)

The same as http_error_301(), but called for the ‘permanent redirect’ response. It does not allow changing the request method from POSTto GET.

Added in version 3.11.

HTTPCookieProcessor Objects

HTTPCookieProcessor instances have one attribute:

HTTPCookieProcessor.cookiejar

The http.cookiejar.CookieJar in which cookies are stored.

ProxyHandler Objects

ProxyHandler._open(request)

The ProxyHandler will have a method <protocol>_open() for every_protocol_ which has a proxy in the proxies dictionary given in the constructor. The method will modify requests to go through the proxy, by calling request.set_proxy(), and call the next handler in the chain to actually execute the protocol.

HTTPPasswordMgr Objects

These methods are available on HTTPPasswordMgr andHTTPPasswordMgrWithDefaultRealm objects.

HTTPPasswordMgr.add_password(realm, uri, user, passwd)

uri can be either a single URI, or a sequence of URIs. realm, user and_passwd_ must be strings. This causes (user, passwd) to be used as authentication tokens when authentication for realm and a super-URI of any of the given URIs is given.

HTTPPasswordMgr.find_user_password(realm, authuri)

Get user/password for given realm and URI, if any. This method will return(None, None) if there is no matching user/password.

For HTTPPasswordMgrWithDefaultRealm objects, the realm None will be searched if the given realm has no matching user/password.

HTTPPasswordMgrWithPriorAuth Objects

This password manager extends HTTPPasswordMgrWithDefaultRealm to support tracking URIs for which authentication credentials should always be sent.

HTTPPasswordMgrWithPriorAuth.add_password(realm, uri, user, passwd, is_authenticated=False)

realm, uri, user, passwd are as forHTTPPasswordMgr.add_password(). is_authenticated sets the initial value of the is_authenticated flag for the given URI or list of URIs. If is_authenticated is specified as True, realm is ignored.

HTTPPasswordMgrWithPriorAuth.find_user_password(realm, authuri)

Same as for HTTPPasswordMgrWithDefaultRealm objects

HTTPPasswordMgrWithPriorAuth.update_authenticated(self, uri, is_authenticated=False)

Update the is_authenticated flag for the given uri or list of URIs.

HTTPPasswordMgrWithPriorAuth.is_authenticated(self, authuri)

Returns the current state of the is_authenticated flag for the given URI.

AbstractBasicAuthHandler Objects

AbstractBasicAuthHandler.http_error_auth_reqed(authreq, host, req, headers)

Handle an authentication request by getting a user/password pair, and re-trying the request. authreq should be the name of the header where the information about the realm is included in the request, host specifies the URL and path to authenticate for, req should be the (failed) Request object, and_headers_ should be the error headers.

host is either an authority (e.g. "python.org") or a URL containing an authority component (e.g. "http://python.org/"). In either case, the authority must not contain a userinfo component (so, "python.org" and"python.org:80" are fine, "joe:password@python.org" is not).

HTTPBasicAuthHandler Objects

HTTPBasicAuthHandler.http_error_401(req, fp, code, msg, hdrs)

Retry the request with authentication information, if available.

ProxyBasicAuthHandler Objects

ProxyBasicAuthHandler.http_error_407(req, fp, code, msg, hdrs)

Retry the request with authentication information, if available.

AbstractDigestAuthHandler Objects

AbstractDigestAuthHandler.http_error_auth_reqed(authreq, host, req, headers)

authreq should be the name of the header where the information about the realm is included in the request, host should be the host to authenticate to, _req_should be the (failed) Request object, and headers should be the error headers.

HTTPDigestAuthHandler Objects

HTTPDigestAuthHandler.http_error_401(req, fp, code, msg, hdrs)

Retry the request with authentication information, if available.

ProxyDigestAuthHandler Objects

ProxyDigestAuthHandler.http_error_407(req, fp, code, msg, hdrs)

Retry the request with authentication information, if available.

HTTPHandler Objects

HTTPHandler.http_open(req)

Send an HTTP request, which can be either GET or POST, depending onreq.has_data().

HTTPSHandler Objects

HTTPSHandler.https_open(req)

Send an HTTPS request, which can be either GET or POST, depending onreq.has_data().

FileHandler Objects

FileHandler.file_open(req)

Open the file locally, if there is no host name, or the host name is'localhost'.

Changed in version 3.2: This method is applicable only for local hostnames. When a remote hostname is given, a URLError is raised.

DataHandler Objects

DataHandler.data_open(req)

Read a data URL. This kind of URL contains the content encoded in the URL itself. The data URL syntax is specified in RFC 2397. This implementation ignores white spaces in base64 encoded data URLs so the URL may be wrapped in whatever source file it comes from. But even though some browsers don’t mind about a missing padding at the end of a base64 encoded data URL, this implementation will raise a ValueError in that case.

FTPHandler Objects

FTPHandler.ftp_open(req)

Open the FTP file indicated by req. The login is always done with empty username and password.

CacheFTPHandler Objects

CacheFTPHandler objects are FTPHandler objects with the following additional methods:

CacheFTPHandler.setTimeout(t)

Set timeout of connections to t seconds.

CacheFTPHandler.setMaxConns(m)

Set maximum number of cached connections to m.

UnknownHandler Objects

UnknownHandler.unknown_open()

Raise a URLError exception.

HTTPErrorProcessor Objects

HTTPErrorProcessor.http_response(request, response)

Process HTTP error responses.

For 200 error codes, the response object is returned immediately.

For non-200 error codes, this simply passes the job on to thehttp_error_<type>() handler methods, via OpenerDirector.error(). Eventually, HTTPDefaultErrorHandler will raise anHTTPError if no other handler handles the error.

HTTPErrorProcessor.https_response(request, response)

Process HTTPS error responses.

The behavior is same as http_response().

Examples

In addition to the examples below, more examples are given inHOWTO Fetch Internet Resources Using The urllib Package.

This example gets the python.org main page and displays the first 300 bytes of it:

import urllib.request with urllib.request.urlopen('http://www.python.org/') as f: ... print(f.read(300)) ... b'\n\n\n<!--[if IE 8]>

Note that urlopen returns a bytes object. This is because there is no way for urlopen to automatically determine the encoding of the byte stream it receives from the HTTP server. In general, a program will decode the returned bytes object to string once it determines or guesses the appropriate encoding.

The following HTML spec document, https://html.spec.whatwg.org/#charset, lists the various ways in which an HTML or an XML document could have specified its encoding information.

For additional information, see the W3C document: https://www.w3.org/International/questions/qa-html-encoding-declarations.

As the python.org website uses utf-8 encoding as specified in its meta tag, we will use the same for decoding the bytes object:

with urllib.request.urlopen('http://www.python.org/') as f: ... print(f.read(100).decode('utf-8')) ...

<!-

It is also possible to achieve the same result without using thecontext manager approach:

import urllib.request f = urllib.request.urlopen('http://www.python.org/') try: ... print(f.read(100).decode('utf-8')) ... finally: ... f.close() ...