Add the npfl138.first_time method.

Author: foxik

labs/npfl138/__init__.py

@@ -24,6 +24,7 @@
 from . import rl_utils
 
 # Utils
+from .first_time import first_time
 from .initializers_override import global_keras_initializers
 from .startup import startup
 from .version import __version__, require_version

labs/npfl138/docs/utilities.md

@@ -3,9 +3,9 @@
 The `npfl138` package also provides a few utilities for startup initialization,
 parameter initialization override, and for version management.
 
-::: npfl138.startup.startup
+::: npfl138.first_time.first_time
     options:
-      heading: npfl138.startup
+      heading: npfl138.first_time
 
 ::: npfl138.global_keras_initializers
 
@@ -15,4 +15,8 @@ parameter initialization override, and for version management.
     options:
       show_root_members_full_path: true
 
+::: npfl138.startup.startup
+    options:
+      heading: npfl138.startup
+
 ::: npfl138.__version__

labs/npfl138/first_time.py

@@ -0,0 +1,16 @@
+# This file is part of NPFL138 <http://github.com/ufal/npfl138/>.
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+seen_tags: set[str] = set()
+
+
+def first_time(tag: str) -> bool:
+    """Returns `True` when first called with the given `tag`."""
+    if tag in seen_tags:
+        return False
+
+    seen_tags.add(tag)
+    return True