Improve usage help messages.

diff --git a/stable.py b/stable.py
index 460c0eee3436c788fc0aa927200dae5dd322f4c3..75b60825afc16f45a1844772990a373c17e39130 100755 (executable)
--- a/stable.py
+++ b/stable.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 from sys import argv, exit as sys_exit
 from os.path import dirname, basename, splitext, join as path_join, exists
-from argparse import ArgumentParser
+from argparse import ArgumentParser, ArgumentDefaultsHelpFormatter
 from random import randint
 from stable.core import ImageMaker
 
@@ -15,30 +15,45 @@ def save_path(count: int) -> str:
 
 
 def parse_args():
-    parser = ArgumentParser(add_help=False)
-    parser.add_argument('-m', '--model')
-    parser.add_argument('-o', '--output')
-    parser.add_argument('-p', '--prompt')
-    parser.add_argument('-H', '--help', action='help')
-    parser.add_argument('--list-schedulers', action='store_true')
-    parser.add_argument('-C', '--copy-params')
-    parser.add_argument('-P', '--model_path_prefix', default='',
-                        help='useful if -m is set from -C as mere filename')
+    parser = ArgumentParser(add_help=False, formatter_class=ArgumentDefaultsHelpFormatter)
+    parser.add_argument('-m', '--model',
+                        help='model filename (-P will pre prefixed, but may '
+                        'also be full path on its own)')
+    parser.add_argument('-o', '--output',
+                        help='output filename or path; if -q > 1, will insert '
+                        'incremented counter number; if no image file '
+                        'extension included, defaults to .png')
+    parser.add_argument('-p', '--prompt',
+                        help='textual guidance to image generation')
+    parser.add_argument('-q', '--quantity', default=1, type=int,
+                        help='how many pictures to generate (with seed '
+                        'auto-incrementing)')
     parser.add_argument('-h', '--height', default=512, type=int,
-                        help='default: 512')
+                        help='target height in pixels')
     parser.add_argument('-w', '--width', default=512, type=int,
-                        help='default: 512')
+                        help='target width in pixels')
     parser.add_argument('-g', '--guidance', default=7.5, type=float,
-                        help='default: 7.5')
+                        help='adherence to text prompt')
     parser.add_argument('-n', '--n_steps', default=15, type=int,
-                        help='default: 15')
-    parser.add_argument('-q', '--quantity', default=1, type=int,
-                        help='default: 1')
+                        help='number of denoising steps')
     parser.add_argument('-s', '--seed', default=1, type=int,
-                        help='default: 1; if set 0, chosen randomnly')
+                        help='randomness seed; set 0 to choose randomly; '
+                        'increments if -q > 1')
     parser.add_argument('-S', '--scheduler', default=DEFAULT_SCHEDULER,
-                        help=f'default: {DEFAULT_SCHEDULER}')
+                        help='name of denoising scheduler; --list-schedulers '
+                        'prints available choices for chosen model')
+    parser.add_argument('-D', '--defaults_from_params_string',
+                        help='string to parse for image generation options '
+                        '(e.g. from image file EXIF comment)')
+    parser.add_argument('-P', '--model_path_prefix',
+                        help='optional directory path prefix to MODEL for '
+                        'where it\'s provided as a mere filename (as may '
+                        'happen due to -D)')
+    parser.add_argument('-H', '--help', action='help')
+    parser.add_argument('-L', '--list-schedulers', action='store_true',
+                        help='list options for -S available with chosen model')
     parsed_args = parser.parse_args()
+    parser.set_defaults(model_path_prefix='')
     if parsed_args.copy_params:
         first_split = parsed_args.copy_params.split('; PROMPT: ', maxsplit=1)
         if 2 == len(first_split):