[kupfer: 4/11] utils: Add parse_time_interval

[Ulrik Sverdrup <usverdrup src gnome org>]

commit 68fb4feb36f65e151bce31cc03c7ce08c377aba8
Author: Ulrik Sverdrup <ulrik sverdrup gmail com>
Date:   Mon Dec 14 00:18:13 2009 +0100

    utils: Add parse_time_interval
    
    Add a simple function to parse time intervals given as strings, will
    understand "1h 2 min" etc and return the number of seconds.

 kupfer/utils.py |   40 ++++++++++++++++++++++++++++++++++++++++
 1 files changed, 40 insertions(+), 0 deletions(-)
---
diff --git a/kupfer/utils.py b/kupfer/utils.py
index 7af7bdf..10bf784 100644
--- a/kupfer/utils.py
+++ b/kupfer/utils.py
@@ -183,3 +183,43 @@ def get_display_path_for_bytestring(filepath):
 	if desc.startswith(homedir) and homedir != desc:
 		desc = desc.replace(homedir, "~/", 1)
 	return desc
+
+def parse_time_interval(tstr):
+	"""
+	Parse a time interval in @tstr, return whole number of seconds
+
+	>>> parse_time_interval("2")
+	2
+	>>> parse_time_interval("1h 2m 5s")
+	3725
+	>>> parse_time_interval("2 min")
+	120
+	"""
+	weights = {
+		"s": 1, "sec": 1,
+		"m": 60, "min": 60,
+		"h": 3600, "hours": 3600,
+	}
+	try:
+		return int(tstr)
+	except ValueError:
+		pass
+
+	total = 0
+	amount = 0
+	# Split the string in runs of digits and runs of characters
+	for isdigit, group in itertools.groupby(tstr, lambda k: k.isdigit()):
+		part = "".join(group).strip()
+		if not part:
+			continue
+		if isdigit:
+			amount = int(part)
+		else:
+			total += amount * weights.get(part.lower(), 0)
+			amount = 0
+	return total
+
+
+if __name__ == '__main__':
+	import doctest
+	doctest.testmod()