Add a way to get the line in a BaseDefinition. Fixes #518.

CHANGELOG.rst

@@ -9,6 +9,7 @@ Changelog
 - Actual semantic completions for the complete Python syntax.
 - Basic type inference for ``yield from`` PEP 380.
 - PEP 484 support (most of the important features of it). Thanks Claude! (@reinhrst)
+- Added ``get_line_code`` to ``Definition`` and ``Completion`` objects.
 - Again a lot of internal changes.
 
 0.9.0 (2015-04-10)

jedi/api/classes.py

@@ -11,6 +11,7 @@ from jedi._compatibility import unicode, use_metaclass
 from jedi import settings
 from jedi import common
 from jedi.parser import tree
+from jedi.parser.utils import load_parser
 from jedi.evaluate.cache import memoize_default, CachedMetaClass
 from jedi.evaluate import representation as er
 from jedi.evaluate import iterable
@@ -360,6 +361,27 @@ class BaseDefinition(object):
     def __repr__(self):
         return "<%s %s>" % (type(self).__name__, self.description)
 
+    def get_line_code(self, before=0, after=0):
+        """
+        Returns the line of code where this object was defined.
+
+        :param before: Add n lines before the current line to the output.
+        :param after: Add n lines after the current line to the output.
+
+        :return str: Returns the line(s) of code or an empty string if it's a
+                     builtin.
+        """
+        if self.in_builtin_module():
+            return ''
+
+        path = self._definition.get_parent_until().path
+        parser = load_parser(path)
+        lines = common.splitlines(parser.source)
+
+        line_nr = self._name.start_pos[0]
+        start_line_nr = line_nr - before
+        return '\n'.join(lines[start_line_nr:line_nr + after + 1])
+
 
 class Completion(BaseDefinition):
     """

jedi/parser/__init__.py

@@ -113,6 +113,7 @@ class Parser(object):
             source += '\n'
             self._added_newline = True
 
+        self.source = source
         self._start_symbol = start_symbol
         self._grammar = grammar
 

jedi/parser/fast.py

@@ -282,6 +282,7 @@ class FastParser(use_metaclass(CachedFastParser)):
         self.number_of_splits = 0
         self.number_of_misses = 0
         self.module.reset_caches()
+        self.source = source
         try:
             self._parse(source)
         except:

test/test_api/test_api.py

@@ -145,3 +145,22 @@ def test_goto_definition_not_multiple():
 def test_usage_description():
     descs = [u.description for u in api.Script("foo = ''; foo").usages()]
     assert set(descs) == set(["foo = ''", 'foo'])
+
+
+def test_get_line_code():
+    def get_line_code(source, line=None, **kwargs):
+        return api.Script(source, line=line).completions()[0].get_line_code(**kwargs)
+
+    # On builtin
+    assert get_line_code('') == ''
+
+    # On custom code
+    line = '    foo'
+    assert get_line_code('def foo():\n%s' % line) == line
+
+    # With before/after
+    line = '    foo'
+    source = 'def foo():\n%s\nother_line' % line
+    assert get_line_code(source, line=2) == line
+    assert get_line_code(source, line=2, after=1) == line + '\nother_line'
+    assert get_line_code(source, line=2, after=1, before=1) == source