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<div class="section" id="module-base64">
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<span id="base64-base16-base32-base64-base85-data-encodings"></span><h1>19.6. <a class="reference internal" href="#module-base64" title="base64: RFC 3548: Base16, Base32, Base64 Data Encodings; Base85 and Ascii85"><code class="xref py py-mod docutils literal"><span class="pre">base64</span></code></a> — Base16, Base32, Base64, Base85 Data Encodings<a class="headerlink" href="#module-base64" title="Permalink to this headline">¶</a></h1>
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<p id="index-0">This module provides functions for encoding binary data to printable
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ASCII characters and decoding such encodings back to binary data.
81
It provides encoding and decoding functions for the encodings specified in
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<span class="target" id="index-1"></span><a class="rfc reference external" href="https://tools.ietf.org/html/rfc3548.html"><strong>RFC 3548</strong></a>, which defines the Base16, Base32, and Base64 algorithms,
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and for the de-facto standard Ascii85 and Base85 encodings.</p>
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<p>The <span class="target" id="index-2"></span><a class="rfc reference external" href="https://tools.ietf.org/html/rfc3548.html"><strong>RFC 3548</strong></a> encodings are suitable for encoding binary data so that it can
85
safely sent by email, used as parts of URLs, or included as part of an HTTP
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POST request. The encoding algorithm is not the same as the
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<strong class="program">uuencode</strong> program.</p>
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<p>There are two interfaces provided by this module. The modern interface
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supports encoding <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like objects</span></a> to ASCII
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<a class="reference internal" href="functions.html#bytes" title="bytes"><code class="xref py py-class docutils literal"><span class="pre">bytes</span></code></a>, and decoding <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like objects</span></a> or
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strings containing ASCII to <a class="reference internal" href="functions.html#bytes" title="bytes"><code class="xref py py-class docutils literal"><span class="pre">bytes</span></code></a>. All three <span class="target" id="index-3"></span><a class="rfc reference external" href="https://tools.ietf.org/html/rfc3548.html"><strong>RFC 3548</strong></a> defined
92
alphabets (normal, URL-safe, and filesystem-safe) are supported.</p>
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<p>The legacy interface does not support decoding from strings, but it does
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provide functions for encoding and decoding to and from <a class="reference internal" href="../glossary.html#term-file-object"><span class="xref std std-term">file objects</span></a>. It only supports the Base64 standard alphabet, and it adds
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newlines every 76 characters as per <span class="target" id="index-4"></span><a class="rfc reference external" href="https://tools.ietf.org/html/rfc2045.html"><strong>RFC 2045</strong></a>. Note that if you are looking
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for <span class="target" id="index-5"></span><a class="rfc reference external" href="https://tools.ietf.org/html/rfc2045.html"><strong>RFC 2045</strong></a> support you probably want to be looking at the <a class="reference internal" href="email.html#module-email" title="email: Package supporting the parsing, manipulating, and generating email messages, including MIME documents."><code class="xref py py-mod docutils literal"><span class="pre">email</span></code></a>
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<div class="versionchanged">
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<p><span class="versionmodified">Changed in version 3.3: </span>ASCII-only Unicode strings are now accepted by the decoding functions of
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the modern interface.</p>
102
<div class="versionchanged">
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<p><span class="versionmodified">Changed in version 3.4: </span>Any <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like object</span></a>s are now accepted by all
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encoding and decoding functions in this module. Ascii85/Base85 support added.</p>
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<p>The modern interface provides:</p>
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<dl class="function">
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<dt id="base64.b64encode">
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<code class="descclassname">base64.</code><code class="descname">b64encode</code><span class="sig-paren">(</span><em>s</em>, <em>altchars=None</em><span class="sig-paren">)</span><a class="headerlink" href="#base64.b64encode" title="Permalink to this definition">¶</a></dt>
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<dd><p>Encode the <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like object</span></a> <em>s</em> using Base64 and return the encoded
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<a class="reference internal" href="functions.html#bytes" title="bytes"><code class="xref py py-class docutils literal"><span class="pre">bytes</span></code></a>.</p>
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<p>Optional <em>altchars</em> must be a <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like object</span></a> of at least
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length 2 (additional characters are ignored) which specifies an alternative
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alphabet for the <code class="docutils literal"><span class="pre">+</span></code> and <code class="docutils literal"><span class="pre">/</span></code> characters. This allows an application to e.g.
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generate URL or filesystem safe Base64 strings. The default is <code class="docutils literal"><span class="pre">None</span></code>, for
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which the standard Base64 alphabet is used.</p>
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<dl class="function">
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<dt id="base64.b64decode">
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<code class="descclassname">base64.</code><code class="descname">b64decode</code><span class="sig-paren">(</span><em>s</em>, <em>altchars=None</em>, <em>validate=False</em><span class="sig-paren">)</span><a class="headerlink" href="#base64.b64decode" title="Permalink to this definition">¶</a></dt>
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<dd><p>Decode the Base64 encoded <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like object</span></a> or ASCII string
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<em>s</em> and return the decoded <a class="reference internal" href="functions.html#bytes" title="bytes"><code class="xref py py-class docutils literal"><span class="pre">bytes</span></code></a>.</p>
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<p>Optional <em>altchars</em> must be a <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like object</span></a> or ASCII string of
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at least length 2 (additional characters are ignored) which specifies the
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alternative alphabet used instead of the <code class="docutils literal"><span class="pre">+</span></code> and <code class="docutils literal"><span class="pre">/</span></code> characters.</p>
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<p>A <a class="reference internal" href="binascii.html#binascii.Error" title="binascii.Error"><code class="xref py py-exc docutils literal"><span class="pre">binascii.Error</span></code></a> exception is raised
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if <em>s</em> is incorrectly padded.</p>
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<p>If <em>validate</em> is <code class="docutils literal"><span class="pre">False</span></code> (the default), non-base64-alphabet characters are
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discarded prior to the padding check. If <em>validate</em> is <code class="docutils literal"><span class="pre">True</span></code>,
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non-base64-alphabet characters in the input result in a
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<a class="reference internal" href="binascii.html#binascii.Error" title="binascii.Error"><code class="xref py py-exc docutils literal"><span class="pre">binascii.Error</span></code></a>.</p>
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<dl class="function">
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<dt id="base64.standard_b64encode">
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<code class="descclassname">base64.</code><code class="descname">standard_b64encode</code><span class="sig-paren">(</span><em>s</em><span class="sig-paren">)</span><a class="headerlink" href="#base64.standard_b64encode" title="Permalink to this definition">¶</a></dt>
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<dd><p>Encode <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like object</span></a> <em>s</em> using the standard Base64 alphabet
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and return the encoded <a class="reference internal" href="functions.html#bytes" title="bytes"><code class="xref py py-class docutils literal"><span class="pre">bytes</span></code></a>.</p>
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<dl class="function">
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<dt id="base64.standard_b64decode">
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<code class="descclassname">base64.</code><code class="descname">standard_b64decode</code><span class="sig-paren">(</span><em>s</em><span class="sig-paren">)</span><a class="headerlink" href="#base64.standard_b64decode" title="Permalink to this definition">¶</a></dt>
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<dd><p>Decode <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like object</span></a> or ASCII string <em>s</em> using the standard
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Base64 alphabet and return the decoded <a class="reference internal" href="functions.html#bytes" title="bytes"><code class="xref py py-class docutils literal"><span class="pre">bytes</span></code></a>.</p>
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<dl class="function">
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<dt id="base64.urlsafe_b64encode">
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<code class="descclassname">base64.</code><code class="descname">urlsafe_b64encode</code><span class="sig-paren">(</span><em>s</em><span class="sig-paren">)</span><a class="headerlink" href="#base64.urlsafe_b64encode" title="Permalink to this definition">¶</a></dt>
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<dd><p>Encode <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like object</span></a> <em>s</em> using a URL-safe alphabet, which
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substitutes <code class="docutils literal"><span class="pre">-</span></code> instead of <code class="docutils literal"><span class="pre">+</span></code> and <code class="docutils literal"><span class="pre">_</span></code> instead of <code class="docutils literal"><span class="pre">/</span></code> in the
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standard Base64 alphabet, and return the encoded <a class="reference internal" href="functions.html#bytes" title="bytes"><code class="xref py py-class docutils literal"><span class="pre">bytes</span></code></a>. The result
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can still contain <code class="docutils literal"><span class="pre">=</span></code>.</p>
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<dl class="function">
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<dt id="base64.urlsafe_b64decode">
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<code class="descclassname">base64.</code><code class="descname">urlsafe_b64decode</code><span class="sig-paren">(</span><em>s</em><span class="sig-paren">)</span><a class="headerlink" href="#base64.urlsafe_b64decode" title="Permalink to this definition">¶</a></dt>
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<dd><p>Decode <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like object</span></a> or ASCII string <em>s</em> using a URL-safe
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alphabet, which substitutes <code class="docutils literal"><span class="pre">-</span></code> instead of <code class="docutils literal"><span class="pre">+</span></code> and <code class="docutils literal"><span class="pre">_</span></code> instead of
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<code class="docutils literal"><span class="pre">/</span></code> in the standard Base64 alphabet, and return the decoded
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<a class="reference internal" href="functions.html#bytes" title="bytes"><code class="xref py py-class docutils literal"><span class="pre">bytes</span></code></a>.</p>
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<dl class="function">
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<dt id="base64.b32encode">
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<code class="descclassname">base64.</code><code class="descname">b32encode</code><span class="sig-paren">(</span><em>s</em><span class="sig-paren">)</span><a class="headerlink" href="#base64.b32encode" title="Permalink to this definition">¶</a></dt>
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<dd><p>Encode the <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like object</span></a> <em>s</em> using Base32 and return the
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encoded <a class="reference internal" href="functions.html#bytes" title="bytes"><code class="xref py py-class docutils literal"><span class="pre">bytes</span></code></a>.</p>
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<dl class="function">
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<dt id="base64.b32decode">
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<code class="descclassname">base64.</code><code class="descname">b32decode</code><span class="sig-paren">(</span><em>s</em>, <em>casefold=False</em>, <em>map01=None</em><span class="sig-paren">)</span><a class="headerlink" href="#base64.b32decode" title="Permalink to this definition">¶</a></dt>
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<dd><p>Decode the Base32 encoded <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like object</span></a> or ASCII string <em>s</em> and
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return the decoded <a class="reference internal" href="functions.html#bytes" title="bytes"><code class="xref py py-class docutils literal"><span class="pre">bytes</span></code></a>.</p>
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<p>Optional <em>casefold</em> is a flag specifying
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whether a lowercase alphabet is acceptable as input. For security purposes,
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the default is <code class="docutils literal"><span class="pre">False</span></code>.</p>
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<p><span class="target" id="index-6"></span><a class="rfc reference external" href="https://tools.ietf.org/html/rfc3548.html"><strong>RFC 3548</strong></a> allows for optional mapping of the digit 0 (zero) to the letter O
183
(oh), and for optional mapping of the digit 1 (one) to either the letter I (eye)
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or letter L (el). The optional argument <em>map01</em> when not <code class="docutils literal"><span class="pre">None</span></code>, specifies
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which letter the digit 1 should be mapped to (when <em>map01</em> is not <code class="docutils literal"><span class="pre">None</span></code>, the
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digit 0 is always mapped to the letter O). For security purposes the default is
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<code class="docutils literal"><span class="pre">None</span></code>, so that 0 and 1 are not allowed in the input.</p>
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<p>A <a class="reference internal" href="binascii.html#binascii.Error" title="binascii.Error"><code class="xref py py-exc docutils literal"><span class="pre">binascii.Error</span></code></a> is raised if <em>s</em> is
189
incorrectly padded or if there are non-alphabet characters present in the
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<dl class="function">
194
<dt id="base64.b16encode">
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<code class="descclassname">base64.</code><code class="descname">b16encode</code><span class="sig-paren">(</span><em>s</em><span class="sig-paren">)</span><a class="headerlink" href="#base64.b16encode" title="Permalink to this definition">¶</a></dt>
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<dd><p>Encode the <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like object</span></a> <em>s</em> using Base16 and return the
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encoded <a class="reference internal" href="functions.html#bytes" title="bytes"><code class="xref py py-class docutils literal"><span class="pre">bytes</span></code></a>.</p>
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<dl class="function">
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<dt id="base64.b16decode">
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<code class="descclassname">base64.</code><code class="descname">b16decode</code><span class="sig-paren">(</span><em>s</em>, <em>casefold=False</em><span class="sig-paren">)</span><a class="headerlink" href="#base64.b16decode" title="Permalink to this definition">¶</a></dt>
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<dd><p>Decode the Base16 encoded <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like object</span></a> or ASCII string <em>s</em> and
204
return the decoded <a class="reference internal" href="functions.html#bytes" title="bytes"><code class="xref py py-class docutils literal"><span class="pre">bytes</span></code></a>.</p>
205
<p>Optional <em>casefold</em> is a flag specifying whether a
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lowercase alphabet is acceptable as input. For security purposes, the default
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is <code class="docutils literal"><span class="pre">False</span></code>.</p>
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<p>A <a class="reference internal" href="exceptions.html#TypeError" title="TypeError"><code class="xref py py-exc docutils literal"><span class="pre">TypeError</span></code></a> is raised if <em>s</em> is
209
incorrectly padded or if there are non-alphabet characters present in the
213
<dl class="function">
214
<dt id="base64.a85encode">
215
<code class="descclassname">base64.</code><code class="descname">a85encode</code><span class="sig-paren">(</span><em>s</em>, <em>*</em>, <em>foldspaces=False</em>, <em>wrapcol=0</em>, <em>pad=False</em>, <em>adobe=False</em><span class="sig-paren">)</span><a class="headerlink" href="#base64.a85encode" title="Permalink to this definition">¶</a></dt>
216
<dd><p>Encode the <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like object</span></a> <em>s</em> using Ascii85 and return the
217
encoded <a class="reference internal" href="functions.html#bytes" title="bytes"><code class="xref py py-class docutils literal"><span class="pre">bytes</span></code></a>.</p>
218
<p><em>foldspaces</em> is an optional flag that uses the special short sequence ‘y’
219
instead of 4 consecutive spaces (ASCII 0x20) as supported by ‘btoa’. This
220
feature is not supported by the “standard” Ascii85 encoding.</p>
221
<p><em>wrapcol</em> controls whether the output should have newline (<code class="docutils literal"><span class="pre">b'\n'</span></code>)
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characters added to it. If this is non-zero, each output line will be
223
at most this many characters long.</p>
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<p><em>pad</em> controls whether the input is padded to a multiple of 4
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before encoding. Note that the <code class="docutils literal"><span class="pre">btoa</span></code> implementation always pads.</p>
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<p><em>adobe</em> controls whether the encoded byte sequence is framed with <code class="docutils literal"><span class="pre"><~</span></code>
227
and <code class="docutils literal"><span class="pre">~></span></code>, which is used by the Adobe implementation.</p>
228
<div class="versionadded">
229
<p><span class="versionmodified">New in version 3.4.</span></p>
233
<dl class="function">
234
<dt id="base64.a85decode">
235
<code class="descclassname">base64.</code><code class="descname">a85decode</code><span class="sig-paren">(</span><em>s</em>, <em>*</em>, <em>foldspaces=False</em>, <em>adobe=False</em>, <em>ignorechars=b' \t\n\r\v'</em><span class="sig-paren">)</span><a class="headerlink" href="#base64.a85decode" title="Permalink to this definition">¶</a></dt>
236
<dd><p>Decode the Ascii85 encoded <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like object</span></a> or ASCII string <em>s</em> and
237
return the decoded <a class="reference internal" href="functions.html#bytes" title="bytes"><code class="xref py py-class docutils literal"><span class="pre">bytes</span></code></a>.</p>
238
<p><em>foldspaces</em> is a flag that specifies whether the ‘y’ short sequence
239
should be accepted as shorthand for 4 consecutive spaces (ASCII 0x20).
240
This feature is not supported by the “standard” Ascii85 encoding.</p>
241
<p><em>adobe</em> controls whether the input sequence is in Adobe Ascii85 format
242
(i.e. is framed with <~ and ~>).</p>
243
<p><em>ignorechars</em> should be a <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like object</span></a> or ASCII string
244
containing characters to ignore
245
from the input. This should only contain whitespace characters, and by
246
default contains all whitespace characters in ASCII.</p>
247
<div class="versionadded">
248
<p><span class="versionmodified">New in version 3.4.</span></p>
252
<dl class="function">
253
<dt id="base64.b85encode">
254
<code class="descclassname">base64.</code><code class="descname">b85encode</code><span class="sig-paren">(</span><em>s</em>, <em>pad=False</em><span class="sig-paren">)</span><a class="headerlink" href="#base64.b85encode" title="Permalink to this definition">¶</a></dt>
255
<dd><p>Encode the <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like object</span></a> <em>s</em> using base85 (as used in e.g.
256
git-style binary diffs) and return the encoded <a class="reference internal" href="functions.html#bytes" title="bytes"><code class="xref py py-class docutils literal"><span class="pre">bytes</span></code></a>.</p>
257
<p>If <em>pad</em> is true, the input is padded with <code class="docutils literal"><span class="pre">b'\0'</span></code> so its length is a
258
multiple of 4 bytes before encoding.</p>
259
<div class="versionadded">
260
<p><span class="versionmodified">New in version 3.4.</span></p>
264
<dl class="function">
265
<dt id="base64.b85decode">
266
<code class="descclassname">base64.</code><code class="descname">b85decode</code><span class="sig-paren">(</span><em>b</em><span class="sig-paren">)</span><a class="headerlink" href="#base64.b85decode" title="Permalink to this definition">¶</a></dt>
267
<dd><p>Decode the base85-encoded <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like object</span></a> or ASCII string <em>b</em> and
268
return the decoded <a class="reference internal" href="functions.html#bytes" title="bytes"><code class="xref py py-class docutils literal"><span class="pre">bytes</span></code></a>. Padding is implicitly removed, if
270
<div class="versionadded">
271
<p><span class="versionmodified">New in version 3.4.</span></p>
275
<div class="admonition note">
276
<p class="first admonition-title">Note</p>
277
<p class="last">Both Base85 and Ascii85 have an expansion factor of 5 to 4 (5 Base85 or
278
Ascii85 characters can encode 4 binary bytes), while the better-known
279
Base64 has an expansion factor of 6 to 4. They are therefore more
280
efficient when space expensive. They differ by details such as the
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character map used for encoding.</p>
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<p>The legacy interface:</p>
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<dl class="function">
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<dt id="base64.decode">
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<code class="descclassname">base64.</code><code class="descname">decode</code><span class="sig-paren">(</span><em>input</em>, <em>output</em><span class="sig-paren">)</span><a class="headerlink" href="#base64.decode" title="Permalink to this definition">¶</a></dt>
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<dd><p>Decode the contents of the binary <em>input</em> file and write the resulting binary
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data to the <em>output</em> file. <em>input</em> and <em>output</em> must be <a class="reference internal" href="../glossary.html#term-file-object"><span class="xref std std-term">file objects</span></a>. <em>input</em> will be read until <code class="docutils literal"><span class="pre">input.readline()</span></code> returns an
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empty bytes object.</p>
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<dl class="function">
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<dt id="base64.decodebytes">
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<code class="descclassname">base64.</code><code class="descname">decodebytes</code><span class="sig-paren">(</span><em>s</em><span class="sig-paren">)</span><a class="headerlink" href="#base64.decodebytes" title="Permalink to this definition">¶</a></dt>
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<dt id="base64.decodestring">
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<code class="descclassname">base64.</code><code class="descname">decodestring</code><span class="sig-paren">(</span><em>s</em><span class="sig-paren">)</span><a class="headerlink" href="#base64.decodestring" title="Permalink to this definition">¶</a></dt>
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<dd><p>Decode the <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like object</span></a> <em>s</em>, which must contain one or more
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lines of base64 encoded data, and return the decoded <a class="reference internal" href="functions.html#bytes" title="bytes"><code class="xref py py-class docutils literal"><span class="pre">bytes</span></code></a>.
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<code class="docutils literal"><span class="pre">decodestring</span></code> is a deprecated alias.</p>
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<div class="versionadded">
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<p><span class="versionmodified">New in version 3.1.</span></p>
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<dl class="function">
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<dt id="base64.encode">
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<code class="descclassname">base64.</code><code class="descname">encode</code><span class="sig-paren">(</span><em>input</em>, <em>output</em><span class="sig-paren">)</span><a class="headerlink" href="#base64.encode" title="Permalink to this definition">¶</a></dt>
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<dd><p>Encode the contents of the binary <em>input</em> file and write the resulting base64
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encoded data to the <em>output</em> file. <em>input</em> and <em>output</em> must be <a class="reference internal" href="../glossary.html#term-file-object"><span class="xref std std-term">file
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objects</span></a>. <em>input</em> will be read until <code class="docutils literal"><span class="pre">input.read()</span></code> returns
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an empty bytes object. <a class="reference internal" href="#base64.encode" title="base64.encode"><code class="xref py py-func docutils literal"><span class="pre">encode()</span></code></a> inserts a newline character (<code class="docutils literal"><span class="pre">b'\n'</span></code>)
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after every 76 bytes of the output, as well as ensuring that the output
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always ends with a newline, as per <span class="target" id="index-7"></span><a class="rfc reference external" href="https://tools.ietf.org/html/rfc2045.html"><strong>RFC 2045</strong></a> (MIME).</p>
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<dl class="function">
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<dt id="base64.encodebytes">
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<code class="descclassname">base64.</code><code class="descname">encodebytes</code><span class="sig-paren">(</span><em>s</em><span class="sig-paren">)</span><a class="headerlink" href="#base64.encodebytes" title="Permalink to this definition">¶</a></dt>
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<dt id="base64.encodestring">
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<code class="descclassname">base64.</code><code class="descname">encodestring</code><span class="sig-paren">(</span><em>s</em><span class="sig-paren">)</span><a class="headerlink" href="#base64.encodestring" title="Permalink to this definition">¶</a></dt>
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<dd><p>Encode the <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like object</span></a> <em>s</em>, which can contain arbitrary binary
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data, and return <a class="reference internal" href="functions.html#bytes" title="bytes"><code class="xref py py-class docutils literal"><span class="pre">bytes</span></code></a> containing the base64-encoded data, with newlines
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(<code class="docutils literal"><span class="pre">b'\n'</span></code>) inserted after every 76 bytes of output, and ensuring that
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there is a trailing newline, as per <span class="target" id="index-8"></span><a class="rfc reference external" href="https://tools.ietf.org/html/rfc2045.html"><strong>RFC 2045</strong></a> (MIME).</p>
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<p><code class="docutils literal"><span class="pre">encodestring</span></code> is a deprecated alias.</p>
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<p>An example usage of the module:</p>
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<div class="highlight-python3"><div class="highlight"><pre><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">base64</span>
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<span class="gp">>>> </span><span class="n">encoded</span> <span class="o">=</span> <span class="n">base64</span><span class="o">.</span><span class="n">b64encode</span><span class="p">(</span><span class="n">b</span><span class="s1">'data to be encoded'</span><span class="p">)</span>
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<span class="gp">>>> </span><span class="n">encoded</span>
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<span class="go">b'ZGF0YSB0byBiZSBlbmNvZGVk'</span>
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<span class="gp">>>> </span><span class="n">data</span> <span class="o">=</span> <span class="n">base64</span><span class="o">.</span><span class="n">b64decode</span><span class="p">(</span><span class="n">encoded</span><span class="p">)</span>
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<span class="gp">>>> </span><span class="n">data</span>
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<span class="go">b'data to be encoded'</span>
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<div class="admonition seealso">
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<p class="first admonition-title">See also</p>
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<dl class="last docutils">
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<dt>Module <a class="reference internal" href="binascii.html#module-binascii" title="binascii: Tools for converting between binary and various ASCII-encoded binary representations."><code class="xref py py-mod docutils literal"><span class="pre">binascii</span></code></a></dt>
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<dd>Support module containing ASCII-to-binary and binary-to-ASCII conversions.</dd>
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<dt><span class="target" id="index-9"></span><a class="rfc reference external" href="https://tools.ietf.org/html/rfc1521.html"><strong>RFC 1521</strong></a> - MIME (Multipurpose Internet Mail Extensions) Part One: Mechanisms for Specifying and Describing the Format of Internet Message Bodies</dt>
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<dd>Section 5.2, “Base64 Content-Transfer-Encoding,” provides the definition of the
345
base64 encoding.</dd>
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