Ensure pygments is optional.

rest_framework/compat.py

@@ -251,6 +251,29 @@ except ImportError:
     apply_markdown = None
 
 
+try:
+    import pygments
+    from pygments.lexers import get_lexer_by_name
+    from pygments.formatters import HtmlFormatter
+
+    def pygments_highlight(text, lang, style):
+        lexer = get_lexer_by_name(lang, stripall=False)
+        formatter = HtmlFormatter(nowrap=True, style=style)
+        return pygments.highlight(text, lexer, formatter)
+
+    def pygments_css(style):
+        formatter = HtmlFormatter(style=style)
+        return formatter.get_style_defs('.highlight')
+
+except ImportError:
+    pygments = None
+
+    def pygments_highlight(text, lang, style):
+        return text
+
+    def pygments_css(style):
+        return None
+
 # `separators` argument to `json.dumps()` differs between 2.x and 3.x
 # See: http://bugs.python.org/issue22767
 if six.PY3:

rest_framework/renderers.py

@@ -25,7 +25,7 @@ from django.utils.html import mark_safe
 from rest_framework import VERSION, exceptions, serializers, status
 from rest_framework.compat import (
     INDENT_SEPARATORS, LONG_SEPARATORS, SHORT_SEPARATORS, coreapi,
-    template_render
+    pygments_css, template_render
 )
 from rest_framework.exceptions import ParseError
 from rest_framework.request import is_form_media_type, override_method
@@ -802,16 +802,13 @@ class DocumentationRenderer(BaseRenderer):
     charset = 'utf-8'
     template = 'rest_framework/docs/index.html'
     code_style = 'emacs'
+    languages = ['shell', 'javascript', 'python']
 
     def get_context(self, data, request):
-        from pygments.formatters import HtmlFormatter
-        formatter = HtmlFormatter(style=self.code_style)
-        code_style = formatter.get_style_defs('.highlight')
-        langs = ['shell', 'javascript', 'python']
         return {
             'document': data,
-            'langs': langs,
-            'code_style': code_style,
+            'langs': self.languages,
+            'code_style': pygments_css(self.code_style),
             'request': request
         }
 

rest_framework/templates/rest_framework/docs/index.html

@@ -16,7 +16,7 @@
 
         <link href="{% static 'rest_framework/docs/img/favicon.ico' %}" rel="shortcut icon">
 
-        <style>{{ code_style }}</style>
+        {% if code_style %}<style>{{ code_style }}</style>{% endif %}
         <script src="{% static 'rest_framework/js/coreapi-0.0.20.js' %}"></script>
         <script src="{% url 'api-docs:schema-js' %}"></script>
 

rest_framework/templatetags/rest_framework.py

@@ -11,7 +11,7 @@ from django.utils.html import escape, format_html, smart_urlquote
 from django.utils.safestring import SafeData, mark_safe
 
 from rest_framework.compat import (
-    NoReverseMatch, markdown, reverse, template_render
+    NoReverseMatch, markdown, reverse, template_render, pygments_highlight
 )
 from rest_framework.renderers import HTMLFormRenderer
 from rest_framework.utils.urls import replace_query_param
@@ -39,14 +39,8 @@ class CodeNode(template.Node):
         self.nodelist = code
 
     def render(self, context):
-        from pygments import highlight
-        from pygments.lexers import get_lexer_by_name
-        from pygments.formatters import HtmlFormatter
-        body = self.nodelist.render(context)
-        lexer = get_lexer_by_name(self.lang, stripall=False)
-        formatter = HtmlFormatter(nowrap=True, style=self.style)
-        code = highlight(body, lexer, formatter)
-        return code
+        text = self.nodelist.render(context)
+        return pygments_highlight(text)
 
 
 @register.filter()