co for Python added

src/exp/py/src/co.py

+import os
+
+class Error(Exception):
+    def __init__(self, status, str):
+        self.status = status
+        self.str = str
+
+    def __str__(self):
+        return self.str
+    
+def translateFilename(name):
+    if name[:1] == '$':
+        idx = name.find('/')
+        env = os.environ.get(name[1:idx])
+        if env == None:
+            return name
+        nname = env + name[idx:]                     
+        return nname
+    else:
+        return name
+    
+def reTranslateFilename(name):
+    idx = name.rfind('/')
+    if idx == -1:
+        return name
+    idx2 = name[:idx].rfind('/')
+    if idx2 == -1:
+        return name
+    
+    dir = name[idx2+1:idx]
+    if name[:idx] == os.environ.get('pwr_' + dir):
+        return '$pwr_' + dir + name[idx:]
+    elif name[:idx] == os.environ.get('pwrp_' + dir):
+        return '$pwrp_' + dir + name[idx:]
+    else:
+        return name