Lockfile custom command, fixup minor things.

[python_utils.git] / config.py

diff --git a/config.py b/config.py
index 58a5e83eb75e8d80f942d59a9309de5f5d4c27f2..81351cff145587adb80cfccf0f245aa7134ef3d6 100644 (file)
--- a/config.py
+++ b/config.py
@@ -69,7 +69,10 @@ import os
 import pprint
 import re
 import sys
-from typing import Any, Dict, List
+from typing import Any, Dict, List, Optional
+
+# This module is commonly used by others in here and should avoid
+# taking any unnecessary dependencies back on them.
 
 # Note: at this point in time, logging hasn't been configured and
 # anything we log will come out the root logger.
@@ -97,10 +100,12 @@ class LoadFromFile(argparse.Action):
 
 
 # A global parser that we will collect arguments into.
+prog = os.path.basename(sys.argv[0])
 args = argparse.ArgumentParser(
-    description=f"This program uses config.py ({__file__}) for global, cross-module configuration.",
+    description=None,
     formatter_class=argparse.ArgumentDefaultsHelpFormatter,
     fromfile_prefix_chars="@",
+    epilog=f'-----------------------------------------------------------------------------\n{prog} uses config.py ({__file__}) for global, cross-module configuration setup and parsing.\n-----------------------------------------------------------------------------'
 )
 config_parse_called = False
 
@@ -152,18 +157,33 @@ def is_flag_already_in_argv(var: str):
     return False
 
 
-def parse() -> Dict[str, Any]:
-    import string_utils
-
+def parse(entry_module: Optional[str]) -> Dict[str, Any]:
     """Main program should call this early in main()"""
     global config_parse_called
     if config_parse_called:
-        return
+        return config
     config_parse_called = True
     global saved_messages
 
+    # If we're about to do the usage message dump, put the main module's
+    # argument group first in the list (if possible), please.
+    reordered_action_groups = []
+    prog = sys.argv[0]
+
+    for arg in sys.argv:
+        if arg == '--help' or arg == '-h':
+            for group in args._action_groups:
+                if entry_module is not None and entry_module in group.title:
+                    reordered_action_groups.insert(0, group)  # prepend
+                elif prog in group.title:
+                    reordered_action_groups.insert(0, group)  # prepend
+                else:
+                    reordered_action_groups.append(group)     # append
+            args._action_groups = reordered_action_groups
+
     # Examine the environment variables to settings that match
-    # known flags.
+    # known flags.  For a flag called --example_flag the corresponding
+    # environment variable would be called EXAMPLE_FLAG.
     usage_message = args.format_usage()
     optional = False
     var = ''
@@ -190,7 +210,8 @@ def parse() -> Dict[str, Any]:
                         saved_messages.append(
                             f'Initialized from environment: {var} = {value}'
                         )
-                        if len(chunks) == 1 and string_utils.to_bool(value):
+                        from string_utils import to_bool
+                        if len(chunks) == 1 and to_bool(value):
                             sys.argv.append(var)
                         elif len(chunks) > 1:
                             sys.argv.append(var)
@@ -201,12 +222,13 @@ def parse() -> Dict[str, Any]:
             next
 
     # Parse (possibly augmented) commandline args with argparse normally.
-    #config.update(vars(args.parse_args()))
     known, unknown = args.parse_known_args()
     config.update(vars(known))
 
     # Reconstruct the argv with unrecognized flags for the benefit of
-    # future argument parsers.
+    # future argument parsers.  For example, unittest_main in python
+    # has some of its own flags.  If we didn't recognize it, maybe
+    # someone else will.
     sys.argv = sys.argv[:1] + unknown
 
     if config['config_savefile']: