Add get_loaded_plugins() function

nonebot/plugin.py

@@ -0,0 +1,72 @@
+import importlib
+import os
+import re
+from collections import namedtuple
+from typing import Set
+
+from .log import logger
+
+Plugin = namedtuple('Plugin', ['module', 'name', 'usage'])
+
+_plugins: Set[Plugin] = set()
+
+
+def load_plugin(module_name: str) -> bool:
+    """
+    Load a module as a plugin.
+
+    :param module_name: name of module to import
+    :return: successful or not
+    """
+    try:
+        module = importlib.import_module(module_name)
+        name = getattr(module, '__plugin_name__', None)
+        usage = getattr(module, '__plugin_usage__', None)
+        _plugins.add(Plugin(module, name, usage))
+        logger.info(f'Succeeded to import "{module_name}"')
+        return True
+    except Exception as e:
+        logger.error(f'Failed to import "{module_name}", error: {e}')
+        logger.exception(e)
+        return False
+
+
+def load_plugins(plugin_dir: str, module_prefix: str) -> int:
+    """
+    Find all non-hidden modules or packages in a given directory,
+    and import them with the given module prefix.
+
+    :param plugin_dir: plugin directory to search
+    :param module_prefix: module prefix used while importing
+    :return: number of plugins successfully loaded
+    """
+    count = 0
+    for name in os.listdir(plugin_dir):
+        path = os.path.join(plugin_dir, name)
+        if os.path.isfile(path) and \
+                (name.startswith('_') or not name.endswith('.py')):
+            continue
+        if os.path.isdir(path) and \
+                (name.startswith('_') or not os.path.exists(
+                    os.path.join(path, '__init__.py'))):
+            continue
+
+        m = re.match(r'([_A-Z0-9a-z]+)(.py)?', name)
+        if not m:
+            continue
+
+        if load_plugin(f'{module_prefix}.{m.group(1)}'):
+            count += 1
+    return count
+
+
+def load_builtin_plugins() -> int:
+    """
+    Load built-in plugins distributed along with "nonebot" package.
+    """
+    plugin_dir = os.path.join(os.path.dirname(__file__), 'plugins')
+    return load_plugins(plugin_dir, 'nonebot.plugins')
+
+
+def get_loaded_plugins() -> Set[Plugin]:
+    return _plugins