command line options for substituting, for use in shell scripts

scripts/codes_configurator.py

@@ -15,7 +15,7 @@ def main():
 
     # load the module
     mod = import_from(args.substitute_py)
-    
+
     # checks - make sure cfields is set and is the correct type 
     if "cfields" not in mod.__dict__:
         raise TypeError("Expected cfields to be defined in " + args.substitute_py)
@@ -24,14 +24,32 @@ def main():
             isinstance(mod.cfields[0][0], str) and \
             isinstance(mod.cfields[0][1], Sequence)):
         raise TypeError("cfields in incorrect format, see usage")
-
+    num_fields = len(mod.cfields)
+    
     # get list of iterators, replacement input, and output labels
     labels      = [ k[0] for k in mod.cfields]
     iterables   = [ k[1].__iter__() for k in mod.cfields]
-    # use two dicts to maintain type information when printing (don't want
-    #  quotes to appear in log file)
     replace_map =     { k[0] : None for k in mod.cfields }
 
+    # process the command line token replacements, adding to labels
+    # and replace_map, but not to iterables
+    if len(args.token_pairs) % 2 != 0:
+        raise ValueError("token pairs must come in twos")
+    elif len(args.token_pairs) > 0:
+        for i in range(0, len(args.token_pairs), 2):
+            k,vstr = args.token_pairs[i],args.token_pairs[i+1]
+            # try making v numeric - fall back to string
+            v = try_num(vstr)
+            if v == None:
+                v = vstr
+            # add pair to replace map and labels (but not iterables!)
+            if k in replace_map:
+                raise ValueError("token " + k + " of token_pairs matches a token "
+                        "given by the substitution py file")
+            else:
+                replace_map[k] = v
+                labels.append(k)
+
     # print the header to the log
     if args.log != None:
         flog = open(args.log, "w")
@@ -43,9 +61,9 @@ def main():
     flog.write("\n")
 
     # generate initial configuration 
-    for i,k in enumerate(labels):
+    for i in range(0,num_fields):
         v = iterables[i].next()
-        replace_map[k] = v
+        replace_map[labels[i]] = v
 
     # main loop 
     ct = 0
@@ -59,27 +77,27 @@ def main():
 
         # print the configuration to the log
         flog.write(str(ct))
-        for i,k in enumerate(labels):
-            if isinstance(replace_map[k], str):
-                flog.write(' "' + replace_map[k] + '"')
+        for l in labels:
+            if isinstance(replace_map[l], str):
+                flog.write(' "' + replace_map[l] + '"')
             else:
-                flog.write(" " + str(replace_map[k]))
+                flog.write(" " + str(replace_map[l]))
         else:
             flog.write('\n')
 
         # generate the next config
-        for i,k in enumerate(labels):
+        for i in range(0,num_fields):
             try:
                 # update current iterable and finish
                 v = iterables[i].next()
-                replace_map[k] = v
+                replace_map[labels[i]] = v
                 ct += 1
                 break
             except StopIteration:
                 # reset the current iterable and set to first element
                 iterables[i] = mod.cfields[i][1].__iter__()
                 v = iterables[i].next()
-                replace_map[k] = v
+                replace_map[labels[i]] = v
         else:
             # last iterable has finished, have generated full set
             break
@@ -118,19 +136,36 @@ def replace_many(st, kv_pairs):
     return pat.sub(lambda match: rep_dict[match.group(0)], st)
 
 def parse_args():
-    parser = argparse.ArgumentParser()
-    parser.add_argument("template",\
+    parser = argparse.ArgumentParser(\
+            description="generate set of configuration files based on template "
+                        "file and replacement tokens")
+    parser.add_argument("template",
             help="template file with replace tokens")
-    parser.add_argument("substitute_py",\
-            help='python file defining "cfields" variable consisting of'\
-                 ' elements of the form ( replacement_token, [replacements...])')
-    parser.add_argument("-l", "--log",\
-            help="log file to write parameterizations to") 
-    parser.add_argument("-o", "--output_prefix",\
+    parser.add_argument("substitute_py",
+            help='python file defining "cfields" variable consisting of '
+                 'elements of the form '
+                 '( replacement_token, [replacements...])')
+    parser.add_argument("token_pairs",
+            nargs='*',
+            help="a list of whitespace-separated token, replace pairs for "
+                 "command-line-driven replacement (useful in shell scripts "
+                 "for generating sets of configuration files with a distinct "
+                 "parameter or for special casing fields)")
+    parser.add_argument("-l", "--log",
+            help="log file to write parameterizations to")
+    parser.add_argument("-o", "--output_prefix",
             help="prefix to output generated configuration files to "
                  "(default: the configuration index appended to the template name)")
     return parser.parse_args()
 
+def try_num(s):
+    try:
+        return int(s)
+    except ValueError:
+        try:
+            return float(s)
+        except ValueError:
+            return None
 
 if __name__ == "__main__":
     main()