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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>18.1.3. email.generator: Generating MIME documents — Python 2.7.5 documentation</title> <link rel="stylesheet" href="../_static/default.css" type="text/css" /> <link rel="stylesheet" href="../_static/pygments.css" type="text/css" /> <script type="text/javascript"> var DOCUMENTATION_OPTIONS = { URL_ROOT: '../', VERSION: '2.7.5', COLLAPSE_INDEX: false, FILE_SUFFIX: '.html', HAS_SOURCE: true }; </script> <script type="text/javascript" src="../_static/jquery.js"></script> <script type="text/javascript" src="../_static/underscore.js"></script> <script type="text/javascript" src="../_static/doctools.js"></script> <script type="text/javascript" src="../_static/sidebar.js"></script> <link rel="search" type="application/opensearchdescription+xml" title="Search within Python 2.7.5 documentation" href="../_static/opensearch.xml"/> <link rel="author" title="About these documents" href="../about.html" /> <link rel="copyright" title="Copyright" href="../copyright.html" /> <link rel="top" title="Python 2.7.5 documentation" href="../index.html" /> <link rel="up" title="18.1. email — An email and MIME handling package" href="email.html" /> <link rel="next" title="18.1.4. email.mime: Creating email and MIME objects from scratch" href="email.mime.html" /> <link rel="prev" title="18.1.2. email.parser: Parsing email messages" href="email.parser.html" /> <link rel="shortcut icon" type="image/png" href="../_static/py.png" /> <script type="text/javascript" src="../_static/copybutton.js"></script> </head> <body> <div class="related"> <h3>Navigation</h3> <ul> <li class="right" style="margin-right: 10px"> <a href="../genindex.html" title="General Index" accesskey="I">index</a></li> <li class="right" > <a href="../py-modindex.html" title="Python Module Index" >modules</a> |</li> <li class="right" > <a href="email.mime.html" title="18.1.4. email.mime: Creating email and MIME objects from scratch" accesskey="N">next</a> |</li> <li class="right" > <a href="email.parser.html" title="18.1.2. email.parser: Parsing email messages" accesskey="P">previous</a> |</li> <li><img src="../_static/py.png" alt="" style="vertical-align: middle; margin-top: -1px"/></li> <li><a href="http://www.python.org/">Python</a> »</li> <li> <a href="../index.html">Python 2.7.5 documentation</a> » </li> <li><a href="index.html" >The Python Standard Library</a> »</li> <li><a href="netdata.html" >18. Internet Data Handling</a> »</li> <li><a href="email.html" accesskey="U">18.1. <tt class="docutils literal"><span class="pre">email</span></tt> — An email and MIME handling package</a> »</li> </ul> </div> <div class="document"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body"> <div class="section" id="module-email.generator"> <span id="email-generator-generating-mime-documents"></span><h1>18.1.3. <a class="reference internal" href="#module-email.generator" title="email.generator: Generate flat text email messages from a message structure."><tt class="xref py py-mod docutils literal"><span class="pre">email.generator</span></tt></a>: Generating MIME documents<a class="headerlink" href="#module-email.generator" title="Permalink to this headline">¶</a></h1> <p>One of the most common tasks is to generate the flat text of the email message represented by a message object structure. You will need to do this if you want to send your message via the <a class="reference internal" href="smtplib.html#module-smtplib" title="smtplib: SMTP protocol client (requires sockets)."><tt class="xref py py-mod docutils literal"><span class="pre">smtplib</span></tt></a> module or the <a class="reference internal" href="nntplib.html#module-nntplib" title="nntplib: NNTP protocol client (requires sockets)."><tt class="xref py py-mod docutils literal"><span class="pre">nntplib</span></tt></a> module, or print the message on the console. Taking a message object structure and producing a flat text document is the job of the <a class="reference internal" href="#email.generator.Generator" title="email.generator.Generator"><tt class="xref py py-class docutils literal"><span class="pre">Generator</span></tt></a> class.</p> <p>Again, as with the <a class="reference internal" href="email.parser.html#module-email.parser" title="email.parser: Parse flat text email messages to produce a message object structure."><tt class="xref py py-mod docutils literal"><span class="pre">email.parser</span></tt></a> module, you aren’t limited to the functionality of the bundled generator; you could write one from scratch yourself. However the bundled generator knows how to generate most email in a standards-compliant way, should handle MIME and non-MIME email messages just fine, and is designed so that the transformation from flat text, to a message structure via the <a class="reference internal" href="email.parser.html#email.parser.Parser" title="email.parser.Parser"><tt class="xref py py-class docutils literal"><span class="pre">Parser</span></tt></a> class, and back to flat text, is idempotent (the input is identical to the output) <a class="footnote-reference" href="#id2" id="id1">[1]</a>. On the other hand, using the Generator on a <a class="reference internal" href="email.message.html#email.message.Message" title="email.message.Message"><tt class="xref py py-class docutils literal"><span class="pre">Message</span></tt></a> constructed by program may result in changes to the <a class="reference internal" href="email.message.html#email.message.Message" title="email.message.Message"><tt class="xref py py-class docutils literal"><span class="pre">Message</span></tt></a> object as defaults are filled in.</p> <p>Here are the public methods of the <a class="reference internal" href="#email.generator.Generator" title="email.generator.Generator"><tt class="xref py py-class docutils literal"><span class="pre">Generator</span></tt></a> class, imported from the <a class="reference internal" href="#module-email.generator" title="email.generator: Generate flat text email messages from a message structure."><tt class="xref py py-mod docutils literal"><span class="pre">email.generator</span></tt></a> module:</p> <dl class="class"> <dt id="email.generator.Generator"> <em class="property">class </em><tt class="descclassname">email.generator.</tt><tt class="descname">Generator</tt><big>(</big><em>outfp</em><span class="optional">[</span>, <em>mangle_from_</em><span class="optional">[</span>, <em>maxheaderlen</em><span class="optional">]</span><span class="optional">]</span><big>)</big><a class="headerlink" href="#email.generator.Generator" title="Permalink to this definition">¶</a></dt> <dd><p>The constructor for the <a class="reference internal" href="#email.generator.Generator" title="email.generator.Generator"><tt class="xref py py-class docutils literal"><span class="pre">Generator</span></tt></a> class takes a file-like object called <em>outfp</em> for an argument. <em>outfp</em> must support the <a class="reference internal" href="#email.generator.Generator.write" title="email.generator.Generator.write"><tt class="xref py py-meth docutils literal"><span class="pre">write()</span></tt></a> method and be usable as the output file in a Python extended print statement.</p> <p>Optional <em>mangle_from_</em> is a flag that, when <tt class="docutils literal"><span class="pre">True</span></tt>, puts a <tt class="docutils literal"><span class="pre">></span></tt> character in front of any line in the body that starts exactly as <tt class="docutils literal"><span class="pre">From</span></tt>, i.e. <tt class="docutils literal"><span class="pre">From</span></tt> followed by a space at the beginning of the line. This is the only guaranteed portable way to avoid having such lines be mistaken for a Unix mailbox format envelope header separator (see <a class="reference external" href="http://www.jwz.org/doc/content-length.html">WHY THE CONTENT-LENGTH FORMAT IS BAD</a> for details). <em>mangle_from_</em> defaults to <tt class="docutils literal"><span class="pre">True</span></tt>, but you might want to set this to <tt class="docutils literal"><span class="pre">False</span></tt> if you are not writing Unix mailbox format files.</p> <p>Optional <em>maxheaderlen</em> specifies the longest length for a non-continued header. When a header line is longer than <em>maxheaderlen</em> (in characters, with tabs expanded to 8 spaces), the header will be split as defined in the <a class="reference internal" href="email.header.html#email.header.Header" title="email.header.Header"><tt class="xref py py-class docutils literal"><span class="pre">Header</span></tt></a> class. Set to zero to disable header wrapping. The default is 78, as recommended (but not required) by <span class="target" id="index-0"></span><a class="rfc reference external" href="http://tools.ietf.org/html/rfc2822.html"><strong>RFC 2822</strong></a>.</p> <p>The other public <a class="reference internal" href="#email.generator.Generator" title="email.generator.Generator"><tt class="xref py py-class docutils literal"><span class="pre">Generator</span></tt></a> methods are:</p> <dl class="method"> <dt id="email.generator.Generator.flatten"> <tt class="descname">flatten</tt><big>(</big><em>msg</em><span class="optional">[</span>, <em>unixfrom</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#email.generator.Generator.flatten" title="Permalink to this definition">¶</a></dt> <dd><p>Print the textual representation of the message object structure rooted at <em>msg</em> to the output file specified when the <a class="reference internal" href="#email.generator.Generator" title="email.generator.Generator"><tt class="xref py py-class docutils literal"><span class="pre">Generator</span></tt></a> instance was created. Subparts are visited depth-first and the resulting text will be properly MIME encoded.</p> <p>Optional <em>unixfrom</em> is a flag that forces the printing of the envelope header delimiter before the first <span class="target" id="index-1"></span><a class="rfc reference external" href="http://tools.ietf.org/html/rfc2822.html"><strong>RFC 2822</strong></a> header of the root message object. If the root object has no envelope header, a standard one is crafted. By default, this is set to <tt class="docutils literal"><span class="pre">False</span></tt> to inhibit the printing of the envelope delimiter.</p> <p>Note that for subparts, no envelope header is ever printed.</p> <p class="versionadded"> <span class="versionmodified">New in version 2.2.2.</span></p> </dd></dl> <dl class="method"> <dt id="email.generator.Generator.clone"> <tt class="descname">clone</tt><big>(</big><em>fp</em><big>)</big><a class="headerlink" href="#email.generator.Generator.clone" title="Permalink to this definition">¶</a></dt> <dd><p>Return an independent clone of this <a class="reference internal" href="#email.generator.Generator" title="email.generator.Generator"><tt class="xref py py-class docutils literal"><span class="pre">Generator</span></tt></a> instance with the exact same options.</p> <p class="versionadded"> <span class="versionmodified">New in version 2.2.2.</span></p> </dd></dl> <dl class="method"> <dt id="email.generator.Generator.write"> <tt class="descname">write</tt><big>(</big><em>s</em><big>)</big><a class="headerlink" href="#email.generator.Generator.write" title="Permalink to this definition">¶</a></dt> <dd><p>Write the string <em>s</em> to the underlying file object, i.e. <em>outfp</em> passed to <a class="reference internal" href="#email.generator.Generator" title="email.generator.Generator"><tt class="xref py py-class docutils literal"><span class="pre">Generator</span></tt></a>‘s constructor. This provides just enough file-like API for <a class="reference internal" href="#email.generator.Generator" title="email.generator.Generator"><tt class="xref py py-class docutils literal"><span class="pre">Generator</span></tt></a> instances to be used in extended print statements.</p> </dd></dl> </dd></dl> <p>As a convenience, see the methods <tt class="xref py py-meth docutils literal"><span class="pre">Message.as_string()</span></tt> and <tt class="docutils literal"><span class="pre">str(aMessage)</span></tt>, a.k.a. <tt class="xref py py-meth docutils literal"><span class="pre">Message.__str__()</span></tt>, which simplify the generation of a formatted string representation of a message object. For more detail, see <a class="reference internal" href="email.message.html#module-email.message" title="email.message: The base class representing email messages."><tt class="xref py py-mod docutils literal"><span class="pre">email.message</span></tt></a>.</p> <p>The <a class="reference internal" href="#module-email.generator" title="email.generator: Generate flat text email messages from a message structure."><tt class="xref py py-mod docutils literal"><span class="pre">email.generator</span></tt></a> module also provides a derived class, called <a class="reference internal" href="#email.generator.DecodedGenerator" title="email.generator.DecodedGenerator"><tt class="xref py py-class docutils literal"><span class="pre">DecodedGenerator</span></tt></a> which is like the <a class="reference internal" href="#email.generator.Generator" title="email.generator.Generator"><tt class="xref py py-class docutils literal"><span class="pre">Generator</span></tt></a> base class, except that non-<em class="mimetype">text</em> parts are substituted with a format string representing the part.</p> <dl class="class"> <dt id="email.generator.DecodedGenerator"> <em class="property">class </em><tt class="descclassname">email.generator.</tt><tt class="descname">DecodedGenerator</tt><big>(</big><em>outfp</em><span class="optional">[</span>, <em>mangle_from_</em><span class="optional">[</span>, <em>maxheaderlen</em><span class="optional">[</span>, <em>fmt</em><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><big>)</big><a class="headerlink" href="#email.generator.DecodedGenerator" title="Permalink to this definition">¶</a></dt> <dd><p>This class, derived from <a class="reference internal" href="#email.generator.Generator" title="email.generator.Generator"><tt class="xref py py-class docutils literal"><span class="pre">Generator</span></tt></a> walks through all the subparts of a message. If the subpart is of main type <em class="mimetype">text</em>, then it prints the decoded payload of the subpart. Optional <em>_mangle_from_</em> and <em>maxheaderlen</em> are as with the <a class="reference internal" href="#email.generator.Generator" title="email.generator.Generator"><tt class="xref py py-class docutils literal"><span class="pre">Generator</span></tt></a> base class.</p> <p>If the subpart is not of main type <em class="mimetype">text</em>, optional <em>fmt</em> is a format string that is used instead of the message payload. <em>fmt</em> is expanded with the following keywords, <tt class="docutils literal"><span class="pre">%(keyword)s</span></tt> format:</p> <ul class="simple"> <li><tt class="docutils literal"><span class="pre">type</span></tt> – Full MIME type of the non-<em class="mimetype">text</em> part</li> <li><tt class="docutils literal"><span class="pre">maintype</span></tt> – Main MIME type of the non-<em class="mimetype">text</em> part</li> <li><tt class="docutils literal"><span class="pre">subtype</span></tt> – Sub-MIME type of the non-<em class="mimetype">text</em> part</li> <li><tt class="docutils literal"><span class="pre">filename</span></tt> – Filename of the non-<em class="mimetype">text</em> part</li> <li><tt class="docutils literal"><span class="pre">description</span></tt> – Description associated with the non-<em class="mimetype">text</em> part</li> <li><tt class="docutils literal"><span class="pre">encoding</span></tt> – Content transfer encoding of the non-<em class="mimetype">text</em> part</li> </ul> <p>The default value for <em>fmt</em> is <tt class="docutils literal"><span class="pre">None</span></tt>, meaning</p> <div class="highlight-python"><pre>[Non-text (%(type)s) part of message omitted, filename %(filename)s]</pre> </div> <p class="versionadded"> <span class="versionmodified">New in version 2.2.2.</span></p> </dd></dl> <p class="versionchanged"> <span class="versionmodified">Changed in version 2.5: </span>The previously deprecated method <a class="reference internal" href="../reference/datamodel.html#object.__call__" title="object.__call__"><tt class="xref py py-meth docutils literal"><span class="pre">__call__()</span></tt></a> was removed.</p> <p class="rubric">Footnotes</p> <table class="docutils footnote" frame="void" id="id2" rules="none"> <colgroup><col class="label" /><col /></colgroup> <tbody valign="top"> <tr><td class="label"><a class="fn-backref" href="#id1">[1]</a></td><td>This statement assumes that you use the appropriate setting for the <tt class="docutils literal"><span class="pre">unixfrom</span></tt> argument, and that you set maxheaderlen=0 (which will preserve whatever the input line lengths were). It is also not strictly true, since in many cases runs of whitespace in headers are collapsed into single blanks. The latter is a bug that will eventually be fixed.</td></tr> </tbody> </table> </div> </div> </div> </div> <div class="sphinxsidebar"> <div class="sphinxsidebarwrapper"> <h4>Previous topic</h4> <p class="topless"><a href="email.parser.html" title="previous chapter">18.1.2. <tt class="docutils literal"><span class="pre">email.parser</span></tt>: Parsing email messages</a></p> <h4>Next topic</h4> <p class="topless"><a href="email.mime.html" title="next chapter">18.1.4. <tt class="docutils literal"><span class="pre">email.mime</span></tt>: Creating email and MIME objects from scratch</a></p> <h3>This Page</h3> <ul class="this-page-menu"> <li><a href="../bugs.html">Report a Bug</a></li> <li><a href="../_sources/library/email.generator.txt" rel="nofollow">Show Source</a></li> </ul> <div id="searchbox" style="display: none"> <h3>Quick search</h3> <form class="search" action="../search.html" method="get"> <input type="text" name="q" /> <input type="submit" value="Go" /> <input type="hidden" name="check_keywords" value="yes" /> <input type="hidden" name="area" value="default" /> </form> <p class="searchtip" style="font-size: 90%"> Enter search terms or a module, class or function name. </p> </div> <script type="text/javascript">$('#searchbox').show(0);</script> </div> </div> <div class="clearer"></div> </div> <div class="related"> <h3>Navigation</h3> <ul> <li class="right" style="margin-right: 10px"> <a href="../genindex.html" title="General Index" >index</a></li> <li class="right" > <a href="../py-modindex.html" title="Python Module Index" >modules</a> |</li> <li class="right" > <a href="email.mime.html" title="18.1.4. email.mime: Creating email and MIME objects from scratch" >next</a> |</li> <li class="right" > <a href="email.parser.html" title="18.1.2. email.parser: Parsing email messages" >previous</a> |</li> <li><img src="../_static/py.png" alt="" style="vertical-align: middle; margin-top: -1px"/></li> <li><a href="http://www.python.org/">Python</a> »</li> <li> <a href="../index.html">Python 2.7.5 documentation</a> » </li> <li><a href="index.html" >The Python Standard Library</a> »</li> <li><a href="netdata.html" >18. 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