Merge pull request #290 from timothycrosley/feature/fix-issue-284

Feature/fix issue 284

2 files changed, 32 insertions, 8 deletions

diff --git a/isort/isort.py b/isort/isort.py
index 1fd5f8be..0acfd815 100644
--- a/isort/isort.py
+++ b/isort/isort.py
@@ -458,7 +458,9 @@ class SortImports(object):
 
                 section_title = self.config.get('import_heading_' + str(section_name).lower(), '')
                 if section_title:
-                    section_output.insert(0, "# " + section_title)
+                    section_comment = "# {0}".format(section_title)
+                    if not section_comment in self.out_lines[0:1]:
+                        section_output.insert(0, section_comment)
                 output += section_output + ['']
 
         while [character.strip() for character in output[-1:]] == [""]:
@@ -603,7 +605,13 @@ class SortImports(object):
 
     def _skip_line(self, line):
         skip_line = self._in_quote
-        if '"' in line or "'" in line:
+        if self.index == 1 and line.startswith("#"):
+            self._in_top_comment = True
+        elif self._in_top_comment:
+            if not line.startswith("#"):
+               self._in_top_comment = False
+               self._first_comment_index_end = self.index
+        elif '"' in line or "'" in line:
             index = 0
             if self._first_comment_index_start == -1:
                 self._first_comment_index_start = self.index
@@ -613,7 +621,7 @@ class SortImports(object):
                 elif self._in_quote:
                     if line[index:index + len(self._in_quote)] == self._in_quote:
                         self._in_quote = False
-                        if self._first_comment_index_end == -1:
+                        if self._first_comment_index_end < self._first_comment_index_start:
                             self._first_comment_index_end = self.index
                 elif line[index] in ("'", '"'):
                     long_quote = line[index:index + 3]
@@ -626,7 +634,7 @@ class SortImports(object):
                     break
                 index += 1
 
-        return skip_line or self._in_quote
+        return skip_line or self._in_quote or self._in_top_comment
 
     def _strip_syntax(self, import_string):
         import_string = import_string.replace("_import", "[[i]]")
@@ -643,6 +651,7 @@ class SortImports(object):
     def _parse(self):
         """Parses a python file taking out and categorizing imports."""
         self._in_quote = False
+        self._in_top_comment = False
         while not self._at_end():
             line = self._get_line()
             skip_line = self._skip_line(line)
@@ -733,11 +742,14 @@ class SortImports(object):
                     if comments:
                         self.comments['from'].setdefault(import_from, []).extend(comments)
 
-                    if len(self.out_lines) > self.import_index:
+                    if len(self.out_lines) > max(self.import_index, self._first_comment_index_end, 1) - 1:
                         last = self.out_lines and self.out_lines[-1].rstrip() or ""
                         while last.startswith("#") and not last.endswith('"""') and not last.endswith("'''"):
                             self.comments['above']['from'].setdefault(import_from, []).insert(0, self.out_lines.pop(-1))
-                            last = self.out_lines and self.out_lines[-1].rstrip() or ""
+                            if len(self.out_lines) > max(self.import_index - 1, self._first_comment_index_end, 1) - 1:
+                                last = self.out_lines[-1].rstrip()
+                            else:
+                                last = ""
 
                     if root.get(import_from, False):
                         root[import_from].update(imports)
@@ -749,11 +761,14 @@ class SortImports(object):
                             self.comments['straight'][module] = comments
                             comments = None
 
-                        if len(self.out_lines) > self.import_index:
+                        if len(self.out_lines) > max(self.import_index, self._first_comment_index_end, 1) - 1:
                             last = self.out_lines and self.out_lines[-1].rstrip() or ""
                             while last.startswith("#") and not last.endswith('"""') and not last.endswith("'''"):
                                 self.comments['above']['from'].setdefault(module, []).insert(0, self.out_lines.pop(-1))
-                                last = self.out_lines and self.out_lines[-1].rstrip() or ""
+                            if len(self.out_lines) > max(self.import_index - 1, self._first_comment_index_end, 1) - 1:
+                                last = self.out_lines[-1].rstrip()
+                            else:
+                                last = ""
                         self.imports[self.place_module(module)][import_type].add(module)
 
 
diff --git a/test_isort.py b/test_isort.py
index 756b1932..dd1c3f63 100644
--- a/test_isort.py
+++ b/test_isort.py
@@ -1441,3 +1441,12 @@ def test_other_file_encodings():
         assert SortImports(file_path=tmp_fname).output == file_contents
     finally:
         shutil.rmtree(tmp_dir, ignore_errors=True)
+
+
+def test_comment_at_top_of_file():
+    """Test to ensure isort correctly handles top of file comments"""
+    test_input = ("# Comment one\n"
+                  "from django import forms\n"
+                  "# Comment two\n"
+                  "from django.contrib.gis.geos import GEOSException\n")
+    assert SortImports(file_contents=test_input).output == test_input