[mod] makes pygments optional in the code

CHANGELOG

@@ -31,6 +31,7 @@ will be for other releases, the workload is already big enough.
 - new helper methods: .next_recursive and .previous_recursive https://redbaron.readthedocs.org/en/latest/other.html
 - fix: doc is tested in CI now, it shouldn't break anymore
 - more rendering test for python3, it shouldn't break anymore
+- pygments is now an optional dependancy, "pip install redbaron" won't install it, "pip install redbaron[pygments"] will
 - new node.next_intuitive and node.previous_intuitive methods for situations where .next/previous doesn't behave the way the user expect it http://redbaron.readthedocs.org/en/latest/other.html#next-intuitive-previous-intuitive
 
 0.5.1 (2015-03-11)

redbaron/base_nodes.py

@@ -9,10 +9,6 @@
 
 from fnmatch import fnmatch
 
-from pygments import highlight
-from pygments.lexers import PythonLexer
-from pygments.formatters import Terminal256Formatter, HtmlFormatter
-
 import baron
 import baron.path
 from baron.utils import python_version, string_instance
@@ -21,8 +17,12 @@
 import redbaron
 
 from redbaron.utils import redbaron_classname_to_baron_type, baron_type_to_redbaron_classname, log, in_a_shell, indent, truncate, HelpLexer
-from redbaron.private_config import runned_from_ipython
+from redbaron.private_config import runned_from_ipython, HAS_PYGMENTS
 
+if HAS_PYGMENTS:
+    from pygments import highlight
+    from pygments.lexers import PythonLexer
+    from pygments.formatters import Terminal256Formatter, HtmlFormatter
 
 if python_version == 3:
     from collections import UserList
@@ -920,7 +920,10 @@ def dumps(self):
 
     def help(self, deep=2, with_formatting=False):
         if runned_from_ipython():
-            sys.stdout.write(highlight(self.__help__(deep=deep, with_formatting=with_formatting) + "\n", HelpLexer(), Terminal256Formatter(style='monokai')))
+            if HAS_PYGMENTS:
+                sys.stdout.write(highlight(self.__help__(deep=deep, with_formatting=with_formatting) + "\n", HelpLexer(), Terminal256Formatter(style='monokai')))
+            else:
+                sys.stdout.write(self.__help__(deep=deep, with_formatting=with_formatting) + "\n")
         else:
             sys.stdout.write(self.__help__(deep=deep, with_formatting=with_formatting) + "\n")
 
@@ -972,9 +975,12 @@ def __repr__(self):
 
     def __str__(self):
         if runned_from_ipython():
-            return highlight(self.dumps(), PythonLexer(encoding="Utf-8"),
-                             Terminal256Formatter(style='monokai',
-                                                  encoding="Utf-8"))
+            if HAS_PYGMENTS:
+                return highlight(self.dumps(), PythonLexer(encoding="Utf-8"),
+                                 Terminal256Formatter(style='monokai',
+                                                      encoding="Utf-8"))
+            else:
+                return self.dumps()
         else:
             return self.dumps()
 

redbaron/nodes.py

@@ -2,14 +2,16 @@
 
 import re
 
-from pygments import highlight
-from pygments.lexers import PythonLexer
-from pygments.formatters import HtmlFormatter
-
 import baron
 from baron.utils import string_instance
 
 from redbaron.base_nodes import Node, NodeList, LiteralyEvaluable, CodeBlockNode, DotProxyList, CommaProxyList, LineProxyList, IfElseBlockSiblingNode, ElseAttributeNode
+from redbaron.private_config import HAS_PYGMENTS
+
+if HAS_PYGMENTS:
+    from pygments import highlight
+    from pygments.lexers import PythonLexer
+    from pygments.formatters import HtmlFormatter
 
 
 class ArgumentGeneratorComprehensionNode(Node):

redbaron/private_config.py

@@ -1,7 +1,18 @@
 ipython_behavior = True
+force_ipython_behavior = False
 DEBUG = False
+HAS_PYGMENTS = True
+
+try:
+    import pygments
+except ImportError:
+    HAS_PYGMENTS = False
 
 def runned_from_ipython():
+    # for testing
+    if force_ipython_behavior:
+        return True
+
     if not ipython_behavior:
         return False
     try:

redbaron/utils.py

@@ -4,12 +4,13 @@
 import re
 import sys
 
-from pygments.token import Comment, Text, String, Keyword, Name, Operator
-from pygments.lexer import RegexLexer, bygroups
-
 from baron.utils import python_version
 
-from redbaron.private_config import DEBUG
+from redbaron.private_config import DEBUG, HAS_PYGMENTS
+
+if HAS_PYGMENTS:
+    from pygments.token import Comment, Text, String, Keyword, Name, Operator
+    from pygments.lexer import RegexLexer, bygroups
 
 if python_version == 3:
     from io import StringIO
@@ -65,18 +66,22 @@ def truncate(text, n):
     return "".join(truncated)
 
 
-class HelpLexer(RegexLexer):
-    name = 'Lexer for RedBaron .help() method output'
-
-    tokens = {
-        'root': [
-            (r"#.*$", Comment),
-            (r"('([^\\']|\\.)*'|\"([^\\\"]|\\.)*\")", String),
-            (r"(None|False|True)", String),
-            (r'(\*)( \w+Node)', bygroups(Operator, Keyword)),
-            (r'\w+Node', Name.Function),
-            (r'(\*|=|->|\(|\)|\.\.\.)', Operator),
-            (r'\w+', Text),
-            (r'\s+', Text),
-        ]
-    }
+if HAS_PYGMENTS:
+    class HelpLexer(RegexLexer):
+        name = 'Lexer for RedBaron .help() method output'
+
+        tokens = {
+            'root': [
+                (r"#.*$", Comment),
+                (r"('([^\\']|\\.)*'|\"([^\\\"]|\\.)*\")", String),
+                (r"(None|False|True)", String),
+                (r'(\*)( \w+Node)', bygroups(Operator, Keyword)),
+                (r'\w+Node', Name.Function),
+                (r'(\*|=|->|\(|\)|\.\.\.)', Operator),
+                (r'\w+', Text),
+                (r'\s+', Text),
+            ]
+        }
+else:
+    class HelpLexer(object):
+        pass