Remove python3 alias (#320)

* Remove python3 alias

* Update test fixtures

---------

Co-authored-by: Mike Fiedler <[email protected]>

Author: verhovsky

readme_renderer/markdown.py

@@ -44,12 +44,6 @@
     warnings.warn(_EXTRA_WARNING)
     variants = {}
 
-# Make code fences with `python` as the language default to highlighting as
-# Python 3.
-_LANG_ALIASES = {
-    'python': 'python3',
-}
-
 
 def render(
     raw: str,
@@ -101,7 +95,6 @@ def _highlight(html: str) -> str:
     def replacer(match: Match[Any]) -> str:
         try:
             lang = match.group('lang')
-            lang = _LANG_ALIASES.get(lang, lang)
             lexer = pygments.lexers.get_lexer_by_name(lang)
         except ValueError:
             lexer = pygments.lexers.TextLexer()

tests/fixtures/test_CommonMark_008.html

@@ -1,5 +1,5 @@
 <p>Here is some Python code for a <code>Dog</code>:</p>
-<pre lang="python3"><span class="k">class</span><span class="w"> </span><span class="nc">Dog</span><span class="p">(</span><span class="n">Animal</span><span class="p">):</span>
+<pre lang="python"><span class="k">class</span><span class="w"> </span><span class="nc">Dog</span><span class="p">(</span><span class="n">Animal</span><span class="p">):</span>
     <span class="k">def</span><span class="w"> </span><span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">name</span><span class="p">):</span>
         <span class="bp">self</span><span class="o">.</span><span class="n">name</span> <span class="o">=</span> <span class="n">name</span>
 

tests/fixtures/test_GFM_doublequotes.html

@@ -1,7 +1,7 @@
 <p>This is normal text.</p>
 <pre><code>This is code text.
 </code></pre>
-<pre lang="python3"><span class="k">def</span><span class="w"> </span><span class="nf">this_is_python</span><span class="p">():</span>
+<pre lang="python"><span class="k">def</span><span class="w"> </span><span class="nf">this_is_python</span><span class="p">():</span>
 <span class="w">    </span><span class="sd">"""This is a docstring."""</span>
     <span class="k">pass</span>
 </pre>

tests/fixtures/test_GFM_highlight.html

@@ -1,7 +1,7 @@
 <p>This is normal text.</p>
 <pre><code>This is code text.
 </code></pre>
-<pre lang="python3"><span class="k">def</span><span class="w"> </span><span class="nf">this_is_python</span><span class="p">():</span>
+<pre lang="python"><span class="k">def</span><span class="w"> </span><span class="nf">this_is_python</span><span class="p">():</span>
     <span class="k">pass</span>
 </pre>
 <pre lang="go"><span class="kd">func</span><span class="w"> </span><span class="nx">ThisIsGo</span><span class="p">(){</span>

tests/fixtures/test_GFM_highlight_default_py.html

@@ -1,4 +1,4 @@
-<pre lang="python3"><span class="k">async</span> <span class="k">def</span><span class="w"> </span><span class="nf">this_is_python</span><span class="p">():</span>
+<pre lang="python"><span class="k">async</span> <span class="k">def</span><span class="w"> </span><span class="nf">this_is_python</span><span class="p">():</span>
     <span class="k">pass</span>
 
 <span class="nb">print</span><span class="p">(</span><span class="k">await</span> <span class="n">this_is_python</span><span class="p">())</span>

tests/fixtures/test_GFM_malicious_pre.html

@@ -1,5 +1,5 @@
 <p>This is normal text.</p>
-<pre lang="python3"><span class="k">def</span><span class="w"> </span><span class="nf">this_is_python</span><span class="p">():</span>
+<pre lang="python"><span class="k">def</span><span class="w"> </span><span class="nf">this_is_python</span><span class="p">():</span>
 <span class="w">    </span><span class="sd">"""This is a docstring."""</span>
     <span class="k">pass</span>
 <span class="o">&lt;</span><span class="n">script</span> <span class="nb">type</span><span class="o">=</span><span class="s2">"text/javascript"</span><span class="o">&gt;</span><span class="n">alert</span><span class="p">(</span><span class="s1">'I am evil.'</span><span class="p">);</span><span class="o">&lt;/</span><span class="n">script</span><span class="o">&gt;</span>