1 files changed, 19 insertions, 0 deletions
diff --git a/_action/count.py b/_action/count.py
new file mode 100644
index 0000000..4130e4f
--- /dev/null
+++ b/_action/count.py
@@ -0,0 +1,19 @@
+# coding: utf-8
+
+import argparse
+
+
+class CountAction(argparse.Action):
+    """argparse action for counting up and down
+
+    parser = argparse.ArgumentParser()
+    parser.add_argument('--verbose', '-v', action=CountAction, const=1, nargs=0)
+    parser.add_argument('--quiet', '-q', action=CountAction, dest='verbose',
+            const=-1, nargs=0)
+    """
+    def __call__(self, parser, namespace, values, option_string=None):
+        try:
+            val = getattr(namespace, self.dest) + self.const
+        except TypeError: # probably None
+            val = self.const
+        setattr(namespace, self.dest, val)