Convert alphanum sort from comparitor to key operator

[htsworkflow.git] / htsworkflow / util / alphanum.py

diff --git a/htsworkflow/util/alphanum.py b/htsworkflow/util/alphanum.py
index c9d66495e76fe672a5c41019ce378358c4ee736b..3729661cc0f5c5199a3ee4779c627ec0d50e9f40 100644 (file)
--- a/htsworkflow/util/alphanum.py
+++ b/htsworkflow/util/alphanum.py
@@ -1,60 +1,13 @@
-#
-# The Alphanum Algorithm is an improved sorting algorithm for strings
-# containing numbers.  Instead of sorting numbers in ASCII order like
-# a standard sort, this algorithm sorts numbers in numeric order.
-#
-# The Alphanum Algorithm is discussed at http://www.DaveKoelle.com
-#
-#* Python implementation provided by Chris Hulan (chris.hulan@gmail.com)
-#* Distributed under same license as original
-#
-# This library is free software; you can redistribute it and/or
-# modify it under the terms of the GNU Lesser General Public
-# License as published by the Free Software Foundation; either
-# version 2.1 of the License, or any later version.
-#
-# This library is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-# Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public
-# License along with this library; if not, write to the Free Software
-# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
-#
+# from http://stackoverflow.com/questions/4836710/does-python-have-a-built-in-function-for-string-natural-sort
+# modified by Diane Trout
 
 import re
-import types
 
-#
-# TODO: Make decimal points be considered in the same class as digits
-#
-
-def chunkify(str):
-    """
-    return a list of numbers and non-numeric substrings of +str+
-    the numeric substrings are converted to integer, non-numeric are left as is
-    """
-    if type(str) in types.StringTypes:
-        chunks = re.findall("(\d+|\D+)",str)
-        #convert numeric strings to numbers
-        chunks = [re.match('\d',x) and int(x) or x for x in chunks]
-        return chunks
-    elif type(str) in [types.IntType, types.LongType, types.FloatType]:
-        return [str]
+def natural_sort_key(s, _nsre=re.compile('([0-9]+)')):
+    if isinstance(s, type("")) or isinstance(s, type(u"")):
+        return [int(text) if text.isdigit() else text.lower()
+                for text in re.split(_nsre, s)]
+    elif isinstance(s, int):
+        return [s]
     else:
-        raise ValueError("Unsupported type %s for input %s" % (type(str), str))
-
-def alphanum(a,b):
-    """
-    breaks +a+ and +b+ into pieces and returns left-to-right comparison of the pieces
-
-    +a+ and +b+ are expected to be strings (for example file names) with numbers and non-numeric characters
-    Split the values into list of numbers and non numeric sub-strings and so comparison of numbers gives
-    Numeric sorting, comparison of non-numeric gives Lexicographic order
-    """
-    # split strings into chunks
-    aChunks = chunkify(a)
-    bChunks = chunkify(b)
-
-    return cmp(aChunks,bChunks) #built in comparison works once data is prepared
+        raise ValueError("Unsupported type %s for input %s" % (type(s), s))