environ import is used only in __main__

[pyderasn.git] / pyderasn.py

diff --git a/pyderasn.py b/pyderasn.py
index 21b4306319db9630c936577b5a7d8595afa717d3..6da6e92706e2186339505e65c7743bc64f14ce89 100755 (executable)
--- a/pyderasn.py
+++ b/pyderasn.py
@@ -75,9 +75,17 @@ tags simultaneously.
 There are :py:func:`pyderasn.tag_ctxp` and :py:func:`pyderasn.tag_ctxc`
 functions, allowing you to easily create ``CONTEXT``
 ``PRIMITIVE``/``CONSTRUCTED`` tags, by specifying only the required tag
-number. Pay attention that explicit tags always have *constructed* tag
-(``tag_ctxc``), but implicit tags for primitive types are primitive
-(``tag_ctxp``).
+number.
+
+.. note::
+
+   EXPLICIT tags always have **constructed** tag. PyDERASN does not
+   explicitly check correctness of schema input here.
+
+.. note::
+
+   Implicit tags have **primitive** (``tag_ctxp``) encoding for
+   primitive values.
 
 ::
 
@@ -663,7 +671,6 @@ from copy import copy
 from datetime import datetime
 from datetime import timedelta
 from math import ceil
-from os import environ
 from string import ascii_letters
 from string import digits
 from sys import version_info
@@ -6366,6 +6373,7 @@ def main():  # pragma: no cover
     if args.defines_by_path is not None:
         ctx["defines_by_path"] = obj_by_path(args.defines_by_path)
     obj, tail = schema().decode(der, ctx=ctx)
+    from os import environ
     print(pprinter(
         obj,
         oid_maps=oid_maps,