Extract common function for counting blank lines

rope/refactor/importutils/module_imports.py

@@ -103,24 +103,16 @@ def _remove_imports(self, imports):
             start, end = stmt.get_old_location()
             blank_lines = 0
             if start != first_import_line:
-              for lineno in range(start - 2, last_index - 1, -1):
-                  if lines[lineno].strip() == '':
-                      blank_lines += 1
-                  else:
-                      break
+                blank_lines = _count_blank_lines(lines.__getitem__, start - 2,
+                                                 last_index - 1, -1)
             after_removing.extend(lines[last_index:start - 1 - blank_lines])
             last_index = end - 1
         after_removing.extend(lines[last_index:])
         return after_removing
 
     def _first_non_blank_line(self, lines, lineno):
-        result = lineno
-        for line in lines[lineno:]:
-            if line.strip() == '':
-                result += 1
-            else:
-                break
-        return result
+        return lineno + _count_blank_lines(lines.__getitem__, lineno,
+                                           len(lines))
 
     def add_import(self, import_info):
         visitor = actions.AddingVisitor(self.project, [import_info])
@@ -236,13 +228,9 @@ def _first_import_line(self):
                 nodes[lineno].lineno)[0]
         else:
             lineno = self.pymodule.lines.length()
-        while lineno > 1:
-            line = self.pymodule.lines.get_line(lineno - 1)
-            if line.strip() == '':
-                lineno -= 1
-            else:
-                break
-        return lineno
+
+        return lineno - _count_blank_lines(self.pymodule.lines.get_line,
+                                           lineno - 1, 1, -1)
 
     def _get_import_name(self, import_stmt):
         import_info = import_stmt.import_info
@@ -292,6 +280,16 @@ def remove_pyname(self, pyname):
             import_stmt.accept(visitor)
 
 
+def _count_blank_lines(get_line, start, end, step=1):
+    count = 0
+    for idx in range(start, end, step):
+        if get_line(idx).strip() == '':
+            count += 1
+        else:
+            break
+    return count
+
+
 class _OneTimeSelector(object):
 
     def __init__(self, names):
@@ -439,24 +437,11 @@ def visit_import(self, node, end_line):
         self.imports.append(import_statement)
 
     def _count_empty_lines_before(self, lineno):
-        result = 0
-        for current in range(lineno - 1, 0, -1):
-            line = self.lines.get_line(current)
-            if line.strip() == '':
-                result += 1
-            else:
-                break
-        return result
+        return _count_blank_lines(self.lines.get_line, lineno - 1, 0, -1)
 
     def _count_empty_lines_after(self, lineno):
-        result = 0
-        for current in range(lineno + 1, self.lines.length()):
-            line = self.lines.get_line(current)
-            if line.strip() == '':
-                result += 1
-            else:
-                break
-        return result
+        return _count_blank_lines(self.lines.get_line, lineno + 1,
+                                  self.lines.length())
 
     def get_separating_line_count(self):
         if not self.imports: