Spider Python Reference Documentation

Spider

Current Version: 10.0.0

Chilkat Spider web crawler object.

Object Creation

obj = chilkat2.Spider()

Properties

AbortCurrent
bool AbortCurrent
Introduced in version 9.5.0.58

When set to True, causes the currently running method to abort. Methods that always finish quickly (i.e.have no length file operations or network communications) are not affected. If no method is running, then this property is automatically reset to False when the next method is called. When the abort occurs, this property is reset to False. Both synchronous and asynchronous method calls can be aborted. (A synchronous method call could be aborted by setting this property from a separate thread.)

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AvoidHttps
bool AvoidHttps

If set the 1 (true) the spider will avoid all HTTPS URLs. The default is 0 (false).

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CacheDir
string CacheDir

Specifies a cache directory to use for spidering. If either of the FetchFromCache or UpdateCache properties are true, this is the location of the cache to be used. Note: the Internet Explorer, Netscape, and FireFox caches are completely separate from the Chilkat Spider cache directory. You should specify a new and empty directory.

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ChopAtQuery
bool ChopAtQuery

If equal to 1 (true), then the query portion of all URLs are automatically removed when adding to the unspidered list. The default value is 0 (false).

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ConnectTimeout
int ConnectTimeout

The maximum number of seconds to wait while connecting to an HTTP server.

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DebugLogFilePath
string DebugLogFilePath

If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.

This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:

  1. a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
  2. the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
  3. there is an internal problem (bug) in the Chilkat code that causes the hang.

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Domain
string Domain (read-only)

The domain name that is being spidered. This is the domain previously set in the Initialize method.

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FetchFromCache
bool FetchFromCache

If equal to 1 (true) then pages are fetched from cache when possible. If 0, the cache is ignored. The default value is 1. Regardless, if no CacheDir is set then the cache is not used.

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FinalRedirectUrl
string FinalRedirectUrl (read-only)
Introduced in version 9.5.0.85

If the last URL crawled was redirected (as indicated by the WasRedirected property), this property will contain the final redirect URL.

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LastErrorHtml
string LastErrorHtml (read-only)

Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorText
string LastErrorText (read-only)

Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorXml
string LastErrorXml (read-only)

Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastFromCache
bool LastFromCache (read-only)

Equal to 1 if the last page spidered was fetched from the cache. Otherwise equal to 0.

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LastHtml
string LastHtml (read-only)

The HTML text of the last paged fetched by the spider.

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LastHtmlDescription
string LastHtmlDescription (read-only)

The HTML META description from the last page fetched by the spider.

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LastHtmlKeywords
string LastHtmlKeywords (read-only)

The HTML META keywords from the last page fetched by the spider.

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LastHtmlTitle
string LastHtmlTitle (read-only)

The HTML title from the last page fetched by the spider.

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LastMethodSuccess
bool LastMethodSuccess

Indicate whether the last method call succeeded or failed. A value of True indicates success, a value of False indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

  • Any method that returns a string.
  • Any method returning a Chilkat object, binary bytes, or a date/time.
  • Any method returning a standard boolean status value where success = True and failure = False.
  • Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to True. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

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LastModDateStr
string LastModDateStr (read-only)

The last modification date/time from the last page fetched by the spider.

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LastUrl
string LastUrl (read-only)

The URL of the last page spidered.

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MaxResponseSize
int MaxResponseSize

The maximum HTTP response size allowed. The spider will automatically fail any pages larger than this size. The default value is 250,000 bytes.

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MaxUrlLen
int MaxUrlLen

The maximum URL length allowed. URLs longer than this are not added to the unspidered list. The default value is 200.

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NumAvoidPatterns
int NumAvoidPatterns (read-only)

The number of avoid patterns previously set by calling AddAvoidPattern.

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NumFailed
int NumFailed (read-only)

The number of URLs in the object's failed URL list.

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NumOutboundLinks
int NumOutboundLinks (read-only)

The number of URLs in the object's outbound links URL list.

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NumSpidered
int NumSpidered (read-only)

The number of URLs in the object's already-spidered URL list.

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NumUnspidered
int NumUnspidered (read-only)

The number of URLs in the object's unspidered URL list.

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PreferIpv6
bool PreferIpv6

If True, then use IPv6 over IPv4 when both are supported for a particular domain. The default value of this property is False, which will choose IPv4 over IPv6.

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ProxyDomain
string ProxyDomain

The domain name of a proxy host if an HTTP proxy is used.

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ProxyLogin
string ProxyLogin

If an HTTP proxy is used and it requires authentication, this property specifies the HTTP proxy login.

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ProxyPassword
string ProxyPassword

If an HTTP proxy is used and it requires authentication, this property specifies the HTTP proxy password.

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ProxyPort
int ProxyPort

The port number of a proxy server if an HTTP proxy is used.

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ReadTimeout
int ReadTimeout

The maximum number of seconds to wait when reading from an HTTP server.

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UpdateCache
bool UpdateCache

If equal to 1 (true) then pages saved to the cache. If 0, the cache is ignored. The default value is 1. Regardless, if no CacheDir is set then the cache is not used.

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UserAgent
string UserAgent

The value of the HTTP user-agent header field to be sent with HTTP requests. This can be set to any desired value, but be aware that some websites may reject requests from unknown user agents.

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VerboseLogging
bool VerboseLogging

If set to True, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is False. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

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Version
string Version (read-only)

Version of the component/library, such as "9.5.0.94"

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WasRedirected
bool WasRedirected (read-only)
Introduced in version 9.5.0.85

Indicates whether the last URL crawled was redirected. (True = yes, False = no)

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WindDownCount
int WindDownCount

The "wind-down" phase begins when this number of URLs has been spidered. When in the wind-down phase, no new URLs are added to the unspidered list. The default value is 0 which means that there is NO wind-down phase.

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Methods

AddAvoidOutboundLinkPattern
void AddAvoidOutboundLinkPattern(string pattern)

Adds a wildcarded pattern to prevent collecting matching outbound link URLs. For example, if "*google*" is added, then any outbound links containing the word "google" will be ignored. The "*" character matches zero or more of any character.

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AddAvoidPattern
void AddAvoidPattern(string pattern)

Adds a wildcarded pattern to prevent spidering matching URLs. For example, if "*register*" is added, then any url containing the word "register" is not spidered. The "*" character matches zero or more of any character.

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AddMustMatchPattern
void AddMustMatchPattern(string pattern)

Adds a wildcarded pattern to limit spidering to only URLs that match the pattern. For example, if "*/products/*" is added, then only URLs containing "/products/" are spidered. This is helpful for only spidering a portion of a website. The "*" character matches zero or more of any character.

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AddUnspidered
void AddUnspidered(string url)

To begin spidering you must call this method one or more times to provide starting points. It adds a single URL to the object's internal queue of URLs to be spidered.

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CanonicalizeUrl
string CanonicalizeUrl(string url)

Canonicalizes a URL by doing the following:

  • Drops username/password if present.
  • Drops fragment if present.
  • Converts domain to lowercase.
  • Removes port 80 or 443
  • Remove default.asp, index.html, index.htm, default.html, index.htm, default.htm, index.php, index.asp, default.php, .cfm, .aspx, ,php3, .pl, .cgi, .txt, .shtml, .phtml
  • Remove www. from the domain if present.

Returns None on failure

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ClearFailedUrls
void ClearFailedUrls()

Clears the object's internal list of URLs that could not be downloaded.

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ClearOutboundLinks
void ClearOutboundLinks()

Clears the object's internal list of outbound URLs that will automatically accumulate while spidering.

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ClearSpideredUrls
void ClearSpideredUrls()

Clears the object's internal list of already-spidered URLs that will automatically accumulate while spidering.

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CrawlNext
bool CrawlNext()

Crawls the next URL in the internal list of unspidered URLs. The URL is moved from the unspidered list to the spidered list. Any new links within the same domain and not yet spidered are added to the unspidered list. (providing that they do not match "avoid" patterns, etc.) Any new outbound links are added to the outbound URL list. If successful, the HTML of the downloaded page is available in the LastHtml property. If there are no more URLs left unspidered, the method returns False. Information about the URL crawled is available in the properties LastUrl, LastFromCache, and LastModDate.

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CrawlNextAsync (1)
Task CrawlNextAsync()

Creates an asynchronous task to call the CrawlNext method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns None on failure

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FetchRobotsText
string FetchRobotsText()

Returns the contents of the robots.txt file from the domain being crawled. This spider object will not crawl URLs excluded by robots.txt. If you believe the spider is not behaving correctly, please notify us at support@chilkatsoft.com and provide information detailing a case that allows us to reproduce the problem.

Returns None on failure

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FetchRobotsTextAsync (1)
Task FetchRobotsTextAsync()

Creates an asynchronous task to call the FetchRobotsText method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns None on failure

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GetAvoidPattern
string GetAvoidPattern(int index)

Returns the Nth avoid pattern previously added by calling AddAvoidPattern. Indexing begins at 0.

Returns None on failure

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GetBaseDomain
string GetBaseDomain(string domain)

Returns the second-level + top-level domain of the domain. For example, if domain is "xyz.example.com", this returns "example.com". For some domains, such as "xyz.example.co.uk", the top 3 levels are returned, such as "example.co.uk".

Returns None on failure

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GetFailedUrl
string GetFailedUrl(int index)

Returns the Nth URL in the failed URL list. Indexing begins at 0.

Returns None on failure

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GetOutboundLink
string GetOutboundLink(int index)

Returns the Nth URL in the outbound link URL list. Indexing begins at 0.

Returns None on failure

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GetSpideredUrl
string GetSpideredUrl(int index)

Returns the Nth URL in the already-spidered URL list. Indexing begins at 0.

Returns None on failure

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GetUnspideredUrl
string GetUnspideredUrl(int index)

Returns the Nth URL in the unspidered URL list. Indexing begins at 0.

Returns None on failure

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GetUrlDomain
string GetUrlDomain(string url)

Returns the domain name part of a URL. For example, if the URL is "https://www.chilkatsoft.com/test.asp", then "www.chilkatsoft.com" is returned.

Returns None on failure

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Initialize
void Initialize(string domain)

Initializes the object to begin spidering a domain. Calling Initialize clears any patterns added via the AddAvoidOutboundLinkPattern, AddAvoidPattern, and AddMustMatchPattern methods. The domain name passed to this method is what is returned by the Domain property. The spider only crawls URLs within the same domain.

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LoadTaskCaller
bool LoadTaskCaller(Task task)
Introduced in version 9.5.0.80

Loads the caller of the task's async method.

Returns True for success, False for failure.

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RecrawlLast
bool RecrawlLast()

Re-crawls the last URL spidered. This helpful when cookies set in a previous page load cause the page to be loaded differently the next time.

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RecrawlLastAsync (1)
Task RecrawlLastAsync()

Creates an asynchronous task to call the RecrawlLast method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns None on failure

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SkipUnspidered
void SkipUnspidered(int index)

Moves a URL from the unspidered list to the spidered list. This allows an application to skip a specific URL.

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SleepMs
void SleepMs(int numMilliseconds)

Suspends the execution of the current thread until the time-out interval elapses.

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