diff --git a/tools/python/jwutils/cast.py b/tools/python/jwutils/cast.py
index 74043d2..1579a35 100644
--- a/tools/python/jwutils/cast.py
+++ b/tools/python/jwutils/cast.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-import pytimeparse
+import pytimeparse, os
 from datetime import datetime, timedelta
 from collections import OrderedDict
 
@@ -97,6 +97,14 @@ def from_str(s: str, target_type=None, default_type=None, throw=True, log_level=
     slog(log_level, msg)
     return None
 
+def from_env(key: str, default=None, target_type=None, default_type=None, throw=True, log_level=WARNING, caller=None): # export
+    val = os.getenv(key)
+    if val is None:
+        return default
+    if target_type is None and default is not None:
+        target_type = type(default)
+    return from_str(val, target_type=target_type, default_type=default_type, throw=throw, log_level=log_level, caller=caller)
+
 # deprecated name
 def cast_str(s: str, target_type=None, default_type=None, throw=True, log_level=WARNING, caller=None):
     return from_str(s, target_type=target_type, default_type=None, throw=True, log_level=WARNING, caller=None)