From d076be098a8cefa1182d5bd3e473780a9f74c066 Mon Sep 17 00:00:00 2001
From: Louis <spalax@gresille.org>
Date: Thu, 5 Nov 2015 18:56:29 +0100
Subject: [PATCH] Add docstring

---
 patacrep/songbook/__main__.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/patacrep/songbook/__main__.py b/patacrep/songbook/__main__.py
index 7006e16f..523cae07 100644
--- a/patacrep/songbook/__main__.py
+++ b/patacrep/songbook/__main__.py
@@ -39,6 +39,10 @@ class VerboseAction(argparse.Action):
         LOGGER.setLevel(logging.DEBUG)
 
 def yesno_type(string):
+    """Interpret argument as a "yes" or a "no".
+
+    Raise `argparse.ArgumentTypeError` if string cannot be analysed.
+    """
     try:
         return yesno(string)
     except ValueError as error: