fixed replace_non_unique so that the prefix can be the same as the se…

…arch string

figurefirst/svg_util.py

@@ -5,12 +5,29 @@ def replace_non_unique(in_filename,out_filename,
                        prefix = ''):
     """parse the document 'in_filename' and replace all 
     instances of the string 'search_string' with the 
-    unique string 'prefix_x' where x is the occurance
-    of the search_string"""
+    unique string 'prefix_x'.
+
+    Parameters
+    ----------
+    in_filename : name of the file to parse
+
+    out_filename : name of the file to write. If 
+        out_filename is the same as in_filename
+        then the old document will be overwritten.
+
+    search_string : target string to search and replace. Note: 
+        when applying this function to svg layout documents
+        take care that you don't target strings that are 
+        common strings in the SVG language. e.g. 'label'
+
+    prefix : the prefix will be appended with a number and used
+        to replace each occurance of the search string.
+     """
+
     with open(in_filename,'rt') as inf:
         strdta = inf.read()
-        n_instances = strdta.count(search_string)
-        for i in range(n_instances):
-            strdta = strdta.replace(search_string, prefix + '_%s'%(i), 1)
+        slist = strdta.split(search_string)
+        outstr = ''.join([s + prefix + '_%s'%(i) for i,s in enumerate(slist[:-1])])
+        outstr += slist[-1]
         with open(out_filename,'wt') as outf:
-            outf.write(strdta)
+            outf.write(outstr)