Doc/lib/liburlparse.tex

   1 \section{Standard Module \sectcode{urlparse}}
   2 \stmodindex{urlparse}
   3 \index{WWW}
   4 \index{World-Wide Web}
   5 \index{URL}
   6 \indexii{URL}{parsing}
   7 \indexii{relative}{URL}
   8
   9 \renewcommand{\indexsubitem}{(in module urlparse)}
  10
  11 This module defines a standard interface to break URL strings up in
  12 components (addessing scheme, network location, path etc.), to combine
  13 the components back into a URL string, and to convert a ``relative
  14 URL'' to an absolute URL given a ``base URL''.
  15
  16 The module has been designed to match the current Internet draft on
  17 Relative Uniform Resource Locators (and discovered a bug in an earlier
  18 draft!).
  19
  20 It defines the following functions:
  21
  22 \begin{funcdesc}{urlparse}{urlstring\optional{\,
  23 default_scheme\optional{\, allow_fragments}}}
  24 Parse a URL into 6 components, returning a 6-tuple: (addressing
  25 scheme, network location, path, parameters, query, fragment
  26 identifier).  This corresponds to the general structure of a URL:
  27 \code{\var{scheme}://\var{netloc}/\var{path};\var{parameters}?\var{query}\#\var{fragment}}.
  28 Each tuple item is a string, possibly empty.
  29 The components are not broken up in smaller parts (e.g. the network
  30 location is a single string), and \% escapes are not expanded.
  31 The delimiters as shown above are not part of the tuple items,
  32 except for a leading slash in the \var{path} component, which is
  33 retained if present.
  34
  35 Example:
  36
  37 \begin{verbatim}
  38 urlparse('http://www.cwi.nl:80/%7Eguido/Python.html')
  39 \end{verbatim}
  40
  41 yields the tuple
  42
  43 \begin{verbatim}
  44 ('http', 'www.cwi.nl:80', '/%7Eguido/Python.html', '', '', '')
  45 \end{verbatim}
  46
  47 If the \var{default_scheme} argument is specified, it gives the
  48 default addressing scheme, to be used only if the URL string does not
  49 specify one.  The default value for this argument is the empty string.
  50
  51 If the \var{allow_fragments} argument is zero, fragment identifiers
  52 are not allowed, even if the URL's addressing scheme normally does
  53 support them.  The default value for this argument is \code{1}.
  54 \end{funcdesc}
  55
  56 \begin{funcdesc}{urlunparse}{tuple}
  57 Construct a URL string from a tuple as returned by \code{urlparse}.
  58 This may result in a slightly different, but equivalent URL, if the
  59 URL that was parsed originally had redundant delimiters, e.g. a ? with
  60 an empty query (the draft states that these are equivalent).
  61 \end{funcdesc}
  62
  63 \begin{funcdesc}{urljoin}{base\, url\optional{\, allow_fragments}}
  64 Construct a full (``absolute'') URL by combining a ``base URL''
  65 (\var{base}) with a ``relative URL'' (\var{url}).  Informally, this
  66 uses components of the base URL, in particular the addressing scheme,
  67 the network location and (part of) the path, to provide missing
  68 components in the relative URL.
  69
  70 Example:
  71
  72 \begin{verbatim}
  73 urljoin('http://www.cwi.nl/%7Eguido/Python.html', 'FAQ.html')
  74 \end{verbatim}
  75
  76 yields the string
  77
  78 \begin{verbatim}
  79 'http://www.cwi.nl/%7Eguido/FAQ.html'
  80 \end{verbatim}
  81
  82 The \var{allow_fragments} argument has the same meaning as for
  83 \code{urlparse}.
  84 \end{funcdesc}