reads DNA sequences in nexus format

readseq.py

@@ -0,0 +1,72 @@
+def patterns():
+
+
+    import re, os, glob, itertools, fnmatch, sys, shutil
+    from itertools import combinations
+    from collections import Counter
+
+    script_dir = os.path.dirname(os.path.realpath(sys.argv[0]))
+    path = os.path.join(script_dir, 'nexus')
+
+
+    genes = []
+    data = {}
+#     print 'Reading nexus files...'
+    for filename in glob.glob(os.path.join(path, '*.nex')):
+
+        m = re.match('(.+).nex', os.path.basename(filename))
+        gene_name = m.group(1)
+#         print 'gene_name=', gene_name
+        genes.append(gene_name)
+        f = open(filename, 'r').read()
+
+        m = re.search('ntax\s*=\s*(\d+)', f, re.M | re.S)
+        ntax = int(m.group(1))
+#         print 'ntax=', ntax
+
+        m = re.search('nchar\s*=\s*(\d+)', f, re.M | re.S)
+        nchar = int(m.group(1))
+#         print 'nchar=', nchar
+
+
+        m = re.search('Matrix\s+(.+?);', f, re.M | re.S)
+        matrix = m.group(1).strip()
+        matrix_lines = matrix.split('\n')
+
+        taxon_names = []
+        sequences = {}
+        sequences_list = []
+        for line in matrix_lines:
+            parts = line.strip().split()
+            assert len(parts) == 2
+            taxon_name = parts[0]
+            sequence = parts[1]
+
+            taxon_names.append(taxon_name)
+            sequences_list.append(sequence)
+            sequences[taxon_name] = sequence
+
+        pattern_list = []
+
+        k=0
+        while k < nchar:
+            site_pattern = ''
+            for i,m in enumerate(sequences_list):
+                site_pattern += m[k]
+            pattern_list.append(site_pattern)
+            k+=1
+        pattern_dict = dict()
+        for i in pattern_list:
+            pattern_dict[i] = pattern_dict.get(i, 0) + 1 
+
+        tmp = []
+        for key in pattern_dict.keys(): ###convert dict to key of tupules
+#             print 'key=', key
+            tmp.append((pattern_dict[key],key))
+
+        sorted_values = sorted(tmp) ###sorted according to key smaller to larger
+        sorted_values.sort(cmp = lambda x,y:cmp(x[1],y[1])) ###sorted according to values in alphabetical order
+
+    return pattern_dict
+
+