Add function to truncate tweet if length will be more than 140 characters

1 files changed, 27 insertions, 0 deletions

diff --git a/last_shout.py b/last_shout.py
index 21a614c..a4b9f82 100755
--- a/last_shout.py
+++ b/last_shout.py
@@ -100,6 +100,32 @@ class TweetRc(object):
             self._config.read(os.path.expanduser('~/.tweetrc'))
         return self._config
 
+def truncate_tweet(s, min_pos=0, max_pos=134, ellipsis=True):
+    NOT_FOUND = -1
+    ERR_MAXMIN = 'Minimum position cannot be greater than maximum position'
+
+    if max_pos < min_pos:
+        raise ValueError(ERR_MAXMIN)
+
+    if ellipsis:
+        suffix = '...'
+    else:
+        suffix = ''
+
+    length = len(s)
+    if length <= max_pos:
+        return s + suffix
+    else:
+        try:
+            # Return it to nearest comma if possible
+            end = s.rindex(',',min_pos,max_pos)
+        except ValueError:
+            # Return string to nearest space
+            end = s.rfind(' ',min_pos,max_pos)
+            if end == NOT_FOUND:
+                end = max_pos
+        return s[0:end] + suffix
+
 def build_string(list):
     '''TODO: Add some error checking to modify string if text'''
     '''      will be more than 140 characters.'''
@@ -115,6 +141,7 @@ def build_string(list):
         elif x == c - 1:
             txt = txt + " & "
             x += 1
+    txt = truncate_tweet(txt, ellipsis=False)
     txt = txt + " #music"
     
     return txt