Fixed remaining pep8 errors

Lib/python/std_pair.i

@@ -176,18 +176,20 @@ SwigPython_std_pair_setitem (PyObject *a, Py_ssize_t b, PyObject *c)
 %define %swig_pair_methods(pair...)
 #if !defined(SWIGPYTHON_BUILTIN)
 %extend {      
-%pythoncode {def __len__(self): return 2
-def __repr__(self): return str((self.first, self.second))
+%pythoncode {def __len__(self):
+    return 2
+def __repr__(self):
+    return str((self.first, self.second))
 def __getitem__(self, index): 
-  if not (index % 2): 
-    return self.first
-  else:
-    return self.second
+    if not (index % 2):
+        return self.first
+    else:
+        return self.second
 def __setitem__(self, index, val):
-  if not (index % 2): 
-    self.first = val
-  else:
-    self.second = val}
+    if not (index % 2):
+        self.first = val
+    else:
+        self.second = val}
 }
 #endif
 %enddef