docstrings updated

README

@@ -1,2 +1,9 @@
 很短但是觉得挺有用的东东
 所以单独立了个项目备份一下
+
+USAGE:
+
+    >>> f = DFAFilter()
+    >>> f.add("sexy")
+    >>> f.filter("hello sexy baby")
+    hello **** baby

filter.py

@@ -13,8 +13,7 @@ class NaiveFilter():
 
     very simple filter implementation
     
-    >>> f = Filter()
-    >>> f = Filter()
+    >>> f = NaiveFilter()
     >>> f.add("sexy")
     >>> f.filter("hello sexy baby")
     hello **** baby
@@ -38,7 +37,7 @@ class BSFilter:
 
     Use Back Sorted Mapping to reduce replacement times
     
-    >>> f = Filter()
+    >>> f = BSFilter()
     >>> f.add("sexy")
     >>> f.filter("hello sexy baby")
     hello **** baby
@@ -86,7 +85,7 @@ class DFAFilter():
 
     Use DFA to keep algorithm perform constantly
     
-    >>> f = Filter()
+    >>> f = DFAFilter()
     >>> f.add("sexy")
     >>> f.filter("hello sexy baby")
     hello **** baby