<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html> <head> <title>Write your own formatter — Pygments</title> <meta http-equiv="content-type" content="text/html; charset=utf-8"> <style type="text/css"> body { background-color: #f2f2f2; margin: 0; padding: 0; font-family: 'Georgia', serif; color: #111; } #content { background-color: white; padding: 20px; margin: 20px auto 20px auto; max-width: 800px; border: 4px solid #ddd; } h1 { font-weight: normal; font-size: 40px; color: #09839A; } h2 { font-weight: normal; font-size: 30px; color: #C73F00; } h1.heading { margin: 0 0 30px 0; } h2.subheading { margin: -30px 0 0 45px; } h3 { margin-top: 30px; } table.docutils { border-collapse: collapse; border: 2px solid #aaa; margin: 0.5em 1.5em 0.5em 1.5em; } table.docutils td { padding: 2px; border: 1px solid #ddd; } p, li, dd, dt, blockquote { font-size: 15px; color: #333; } p { line-height: 150%; margin-bottom: 0; margin-top: 10px; } hr { border-top: 1px solid #ccc; border-bottom: 0; border-right: 0; border-left: 0; margin-bottom: 10px; margin-top: 20px; } dl { margin-left: 10px; } li, dt { margin-top: 5px; } dt { font-weight: bold; } th { text-align: left; } a { color: #990000; } a:hover { color: #c73f00; } pre { background-color: #f9f9f9; border-top: 1px solid #ccc; border-bottom: 1px solid #ccc; padding: 5px; font-size: 13px; font-family: Bitstream Vera Sans Mono,monospace; } tt { font-size: 13px; font-family: Bitstream Vera Sans Mono,monospace; color: black; padding: 1px 2px 1px 2px; background-color: #f0f0f0; } cite { /* abusing <cite>, it's generated by ReST for `x` */ font-size: 13px; font-family: Bitstream Vera Sans Mono,monospace; font-weight: bold; font-style: normal; } #backlink { float: right; font-size: 11px; color: #888; } div.toc { margin: 0 0 10px 0; } div.toc h2 { font-size: 20px; } .syntax .hll { background-color: #ffffcc } .syntax { background: #ffffff; } .syntax .c { color: #888888 } /* Comment */ .syntax .err { color: #a61717; background-color: #e3d2d2 } /* Error */ .syntax .k { color: #008800; font-weight: bold } /* Keyword */ .syntax .cm { color: #888888 } /* Comment.Multiline */ .syntax .cp { color: #cc0000; font-weight: bold } /* Comment.Preproc */ .syntax .c1 { color: #888888 } /* Comment.Single */ .syntax .cs { color: #cc0000; font-weight: bold; background-color: #fff0f0 } /* Comment.Special */ .syntax .gd { color: #000000; background-color: #ffdddd } /* Generic.Deleted */ .syntax .ge { font-style: italic } /* Generic.Emph */ .syntax .gr { color: #aa0000 } /* Generic.Error */ .syntax .gh { color: #303030 } /* Generic.Heading */ .syntax .gi { color: #000000; background-color: #ddffdd } /* Generic.Inserted */ .syntax .go { color: #888888 } /* Generic.Output */ .syntax .gp { color: #555555 } /* Generic.Prompt */ .syntax .gs { font-weight: bold } /* Generic.Strong */ .syntax .gu { color: #606060 } /* Generic.Subheading */ .syntax .gt { color: #aa0000 } /* Generic.Traceback */ .syntax .kc { color: #008800; font-weight: bold } /* Keyword.Constant */ .syntax .kd { color: #008800; font-weight: bold } /* Keyword.Declaration */ .syntax .kn { color: #008800; font-weight: bold } /* Keyword.Namespace */ .syntax .kp { color: #008800 } /* Keyword.Pseudo */ .syntax .kr { color: #008800; font-weight: bold } /* Keyword.Reserved */ .syntax .kt { color: #888888; font-weight: bold } /* Keyword.Type */ .syntax .m { color: #0000DD; font-weight: bold } /* Literal.Number */ .syntax .s { color: #dd2200; background-color: #fff0f0 } /* Literal.String */ .syntax .na { color: #336699 } /* Name.Attribute */ .syntax .nb { color: #003388 } /* Name.Builtin */ .syntax .nc { color: #bb0066; font-weight: bold } /* Name.Class */ .syntax .no { color: #003366; font-weight: bold } /* Name.Constant */ .syntax .nd { color: #555555 } /* Name.Decorator */ .syntax .ne { color: #bb0066; font-weight: bold } /* Name.Exception */ .syntax .nf { color: #0066bb; font-weight: bold } /* Name.Function */ .syntax .nl { color: #336699; font-style: italic } /* Name.Label */ .syntax .nn { color: #bb0066; font-weight: bold } /* Name.Namespace */ .syntax .py { color: #336699; font-weight: bold } /* Name.Property */ .syntax .nt { color: #bb0066; font-weight: bold } /* Name.Tag */ .syntax .nv { color: #336699 } /* Name.Variable */ .syntax .ow { color: #008800 } /* Operator.Word */ .syntax .w { color: #bbbbbb } /* Text.Whitespace */ .syntax .mf { color: #0000DD; font-weight: bold } /* Literal.Number.Float */ .syntax .mh { color: #0000DD; font-weight: bold } /* Literal.Number.Hex */ .syntax .mi { color: #0000DD; font-weight: bold } /* Literal.Number.Integer */ .syntax .mo { color: #0000DD; font-weight: bold } /* Literal.Number.Oct */ .syntax .sb { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Backtick */ .syntax .sc { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Char */ .syntax .sd { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Doc */ .syntax .s2 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Double */ .syntax .se { color: #0044dd; background-color: #fff0f0 } /* Literal.String.Escape */ .syntax .sh { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Heredoc */ .syntax .si { color: #3333bb; background-color: #fff0f0 } /* Literal.String.Interpol */ .syntax .sx { color: #22bb22; background-color: #f0fff0 } /* Literal.String.Other */ .syntax .sr { color: #008800; background-color: #fff0ff } /* Literal.String.Regex */ .syntax .s1 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Single */ .syntax .ss { color: #aa6600; background-color: #fff0f0 } /* Literal.String.Symbol */ .syntax .bp { color: #003388 } /* Name.Builtin.Pseudo */ .syntax .vc { color: #336699 } /* Name.Variable.Class */ .syntax .vg { color: #dd7700 } /* Name.Variable.Global */ .syntax .vi { color: #3333bb } /* Name.Variable.Instance */ .syntax .il { color: #0000DD; font-weight: bold } /* Literal.Number.Integer.Long */ </style> </head> <body> <div id="content"> <h1 class="heading">Pygments</h1> <h2 class="subheading">Write your own formatter</h2> <a id="backlink" href="index.html">« Back To Index</a> <div class="toc"> <h2>Contents</h2> <ul class="contents"> <li><a href="#quickstart">Quickstart</a></li> <li><a href="#styles">Styles</a></li> <li><a href="#html-3-2-formatter">HTML 3.2 Formatter</a></li> <li><a href="#generating-style-definitions">Generating Style Definitions</a></li> </ul> </div> <!-- -*- mode: rst -*- --> <p>As well as creating <a class="reference external" href="./lexerdevelopment.html">your own lexer</a>, writing a new formatter for Pygments is easy and straightforward.</p> <p>A formatter is a class that is initialized with some keyword arguments (the formatter options) and that must provides a <cite>format()</cite> method. Additionally a formatter should provide a <cite>get_style_defs()</cite> method that returns the style definitions from the style in a form usable for the formatter's output format.</p> <div class="section" id="quickstart"> <h3>Quickstart</h3> <p>The most basic formatter shipped with Pygments is the <cite>NullFormatter</cite>. It just sends the value of a token to the output stream:</p> <div class="syntax"><pre><span class="kn">from</span> <span class="nn">pygments.formatter</span> <span class="kn">import</span> <span class="n">Formatter</span> <span class="k">class</span> <span class="nc">NullFormatter</span><span class="p">(</span><span class="n">Formatter</span><span class="p">):</span> <span class="k">def</span> <span class="nf">format</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">tokensource</span><span class="p">,</span> <span class="n">outfile</span><span class="p">):</span> <span class="k">for</span> <span class="n">ttype</span><span class="p">,</span> <span class="n">value</span> <span class="ow">in</span> <span class="n">tokensource</span><span class="p">:</span> <span class="n">outfile</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="n">value</span><span class="p">)</span> </pre></div> <p>As you can see, the <cite>format()</cite> method is passed two parameters: <cite>tokensource</cite> and <cite>outfile</cite>. The first is an iterable of <tt class="docutils literal">(token_type, value)</tt> tuples, the latter a file like object with a <cite>write()</cite> method.</p> <p>Because the formatter is that basic it doesn't overwrite the <cite>get_style_defs()</cite> method.</p> </div> <div class="section" id="styles"> <h3>Styles</h3> <p>Styles aren't instantiated but their metaclass provides some class functions so that you can access the style definitions easily.</p> <p>Styles are iterable and yield tuples in the form <tt class="docutils literal">(ttype, d)</tt> where <cite>ttype</cite> is a token and <cite>d</cite> is a dict with the following keys:</p> <dl class="docutils"> <dt><tt class="docutils literal">'color'</tt></dt> <dd>Hexadecimal color value (eg: <tt class="docutils literal">'ff0000'</tt> for red) or <cite>None</cite> if not defined.</dd> <dt><tt class="docutils literal">'bold'</tt></dt> <dd><cite>True</cite> if the value should be bold</dd> <dt><tt class="docutils literal">'italic'</tt></dt> <dd><cite>True</cite> if the value should be italic</dd> <dt><tt class="docutils literal">'underline'</tt></dt> <dd><cite>True</cite> if the value should be underlined</dd> <dt><tt class="docutils literal">'bgcolor'</tt></dt> <dd>Hexadecimal color value for the background (eg: <tt class="docutils literal">'eeeeeee'</tt> for light gray) or <cite>None</cite> if not defined.</dd> <dt><tt class="docutils literal">'border'</tt></dt> <dd>Hexadecimal color value for the border (eg: <tt class="docutils literal">'0000aa'</tt> for a dark blue) or <cite>None</cite> for no border.</dd> </dl> <p>Additional keys might appear in the future, formatters should ignore all keys they don't support.</p> </div> <div class="section" id="html-3-2-formatter"> <h3>HTML 3.2 Formatter</h3> <p>For an more complex example, let's implement a HTML 3.2 Formatter. We don't use CSS but inline markup (<tt class="docutils literal"><u></tt>, <tt class="docutils literal"><font></tt>, etc). Because this isn't good style this formatter isn't in the standard library ;-)</p> <div class="syntax"><pre><span class="kn">from</span> <span class="nn">pygments.formatter</span> <span class="kn">import</span> <span class="n">Formatter</span> <span class="k">class</span> <span class="nc">OldHtmlFormatter</span><span class="p">(</span><span class="n">Formatter</span><span class="p">):</span> <span class="k">def</span> <span class="nf">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">**</span><span class="n">options</span><span class="p">):</span> <span class="n">Formatter</span><span class="o">.</span><span class="n">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">**</span><span class="n">options</span><span class="p">)</span> <span class="c"># create a dict of (start, end) tuples that wrap the</span> <span class="c"># value of a token so that we can use it in the format</span> <span class="c"># method later</span> <span class="bp">self</span><span class="o">.</span><span class="n">styles</span> <span class="o">=</span> <span class="p">{}</span> <span class="c"># we iterate over the `_styles` attribute of a style item</span> <span class="c"># that contains the parsed style values.</span> <span class="k">for</span> <span class="n">token</span><span class="p">,</span> <span class="n">style</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">style</span><span class="p">:</span> <span class="n">start</span> <span class="o">=</span> <span class="n">end</span> <span class="o">=</span> <span class="s">''</span> <span class="c"># a style item is a tuple in the following form:</span> <span class="c"># colors are readily specified in hex: 'RRGGBB'</span> <span class="k">if</span> <span class="n">style</span><span class="p">[</span><span class="s">'color'</span><span class="p">]:</span> <span class="n">start</span> <span class="o">+=</span> <span class="s">'<font color="#</span><span class="si">%s</span><span class="s">">'</span> <span class="o">%</span> <span class="n">style</span><span class="p">[</span><span class="s">'color'</span><span class="p">]</span> <span class="n">end</span> <span class="o">=</span> <span class="s">'</font>'</span> <span class="o">+</span> <span class="n">end</span> <span class="k">if</span> <span class="n">style</span><span class="p">[</span><span class="s">'bold'</span><span class="p">]:</span> <span class="n">start</span> <span class="o">+=</span> <span class="s">'<b>'</span> <span class="n">end</span> <span class="o">=</span> <span class="s">'</b>'</span> <span class="o">+</span> <span class="n">end</span> <span class="k">if</span> <span class="n">style</span><span class="p">[</span><span class="s">'italic'</span><span class="p">]:</span> <span class="n">start</span> <span class="o">+=</span> <span class="s">'<i>'</span> <span class="n">end</span> <span class="o">=</span> <span class="s">'</i>'</span> <span class="o">+</span> <span class="n">end</span> <span class="k">if</span> <span class="n">style</span><span class="p">[</span><span class="s">'underline'</span><span class="p">]:</span> <span class="n">start</span> <span class="o">+=</span> <span class="s">'<u>'</span> <span class="n">end</span> <span class="o">=</span> <span class="s">'</u>'</span> <span class="o">+</span> <span class="n">end</span> <span class="bp">self</span><span class="o">.</span><span class="n">styles</span><span class="p">[</span><span class="n">token</span><span class="p">]</span> <span class="o">=</span> <span class="p">(</span><span class="n">start</span><span class="p">,</span> <span class="n">end</span><span class="p">)</span> <span class="k">def</span> <span class="nf">format</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">tokensource</span><span class="p">,</span> <span class="n">outfile</span><span class="p">):</span> <span class="c"># lastval is a string we use for caching</span> <span class="c"># because it's possible that an lexer yields a number</span> <span class="c"># of consecutive tokens with the same token type.</span> <span class="c"># to minimize the size of the generated html markup we</span> <span class="c"># try to join the values of same-type tokens here</span> <span class="n">lastval</span> <span class="o">=</span> <span class="s">''</span> <span class="n">lasttype</span> <span class="o">=</span> <span class="bp">None</span> <span class="c"># wrap the whole output with <pre></span> <span class="n">outfile</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="s">'<pre>'</span><span class="p">)</span> <span class="k">for</span> <span class="n">ttype</span><span class="p">,</span> <span class="n">value</span> <span class="ow">in</span> <span class="n">tokensource</span><span class="p">:</span> <span class="c"># if the token type doesn't exist in the stylemap</span> <span class="c"># we try it with the parent of the token type</span> <span class="c"># eg: parent of Token.Literal.String.Double is</span> <span class="c"># Token.Literal.String</span> <span class="k">while</span> <span class="n">ttype</span> <span class="ow">not</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">styles</span><span class="p">:</span> <span class="n">ttype</span> <span class="o">=</span> <span class="n">ttype</span><span class="o">.</span><span class="n">parent</span> <span class="k">if</span> <span class="n">ttype</span> <span class="o">==</span> <span class="n">lasttype</span><span class="p">:</span> <span class="c"># the current token type is the same of the last</span> <span class="c"># iteration. cache it</span> <span class="n">lastval</span> <span class="o">+=</span> <span class="n">value</span> <span class="k">else</span><span class="p">:</span> <span class="c"># not the same token as last iteration, but we</span> <span class="c"># have some data in the buffer. wrap it with the</span> <span class="c"># defined style and write it to the output file</span> <span class="k">if</span> <span class="n">lastval</span><span class="p">:</span> <span class="n">stylebegin</span><span class="p">,</span> <span class="n">styleend</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">styles</span><span class="p">[</span><span class="n">lasttype</span><span class="p">]</span> <span class="n">outfile</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="n">stylebegin</span> <span class="o">+</span> <span class="n">lastval</span> <span class="o">+</span> <span class="n">styleend</span><span class="p">)</span> <span class="c"># set lastval/lasttype to current values</span> <span class="n">lastval</span> <span class="o">=</span> <span class="n">value</span> <span class="n">lasttype</span> <span class="o">=</span> <span class="n">ttype</span> <span class="c"># if something is left in the buffer, write it to the</span> <span class="c"># output file, then close the opened <pre> tag</span> <span class="k">if</span> <span class="n">lastval</span><span class="p">:</span> <span class="n">stylebegin</span><span class="p">,</span> <span class="n">styleend</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">styles</span><span class="p">[</span><span class="n">lasttype</span><span class="p">]</span> <span class="n">outfile</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="n">stylebegin</span> <span class="o">+</span> <span class="n">lastval</span> <span class="o">+</span> <span class="n">styleend</span><span class="p">)</span> <span class="n">outfile</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="s">'</pre></span><span class="se">\n</span><span class="s">'</span><span class="p">)</span> </pre></div> <p>The comments should explain it. Again, this formatter doesn't override the <cite>get_style_defs()</cite> method. If we would have used CSS classes instead of inline HTML markup, we would need to generate the CSS first. For that purpose the <cite>get_style_defs()</cite> method exists:</p> </div> <div class="section" id="generating-style-definitions"> <h3>Generating Style Definitions</h3> <p>Some formatters like the <cite>LatexFormatter</cite> and the <cite>HtmlFormatter</cite> don't output inline markup but reference either macros or css classes. Because the definitions of those are not part of the output, the <cite>get_style_defs()</cite> method exists. It is passed one parameter (if it's used and how it's used is up to the formatter) and has to return a string or <tt class="docutils literal">None</tt>.</p> </div> </div> </body> <!-- generated on: 2010-03-01 21:18:23.141347 file id: formatterdevelopment --> </html>