Add public positive_int and finite_float converters (#5969)

Co-authored-by: Kreusada <67752638+Kreusada@users.noreply.github.com>

redbot/core/commands/__init__.py

@@ -28,10 +28,12 @@ from .converter import (
     DictConverter as DictConverter,
     RelativedeltaConverter as RelativedeltaConverter,
     TimedeltaConverter as TimedeltaConverter,
+    finite_float as finite_float,
     get_dict_converter as get_dict_converter,
     get_timedelta_converter as get_timedelta_converter,
     parse_relativedelta as parse_relativedelta,
     parse_timedelta as parse_timedelta,
+    positive_int as positive_int,
     NoParseOptional as NoParseOptional,
     UserInputOptional as UserInputOptional,
     RawUserIdConverter as RawUserIdConverter,

redbot/core/commands/converter.py

@@ -6,6 +6,7 @@ This module contains useful functions and classes for command argument conversio
 Some of the converters within are included provisionally and are marked as such.
 """
 import functools
+import math
 import re
 from datetime import timedelta
 from dateutil.relativedelta import relativedelta
@@ -37,10 +38,12 @@ __all__ = [
     "NoParseOptional",
     "RelativedeltaConverter",
     "TimedeltaConverter",
+    "finite_float",
     "get_dict_converter",
     "get_timedelta_converter",
     "parse_relativedelta",
     "parse_timedelta",
+    "positive_int",
     "CommandConverter",
     "CogConverter",
 ]
@@ -233,6 +236,26 @@ class RawUserIdConverter(dpy_commands.Converter):
 # which is *not* for type checking for the actual implementation
 # and ensure the lies stay correct for how the object should look as a typehint
 
+positive_int = dpy_commands.Range[int, 0, None]
+
+
+if TYPE_CHECKING:
+    finite_float = float
+else:
+
+    def finite_float(arg: str) -> float:
+        """
+        This converts a user provided string into a finite float.
+        """
+        try:
+            ret = float(arg)
+        except ValueError:
+            raise BadArgument(_("`{arg}` is not a number.").format(arg=arg))
+        if not math.isfinite(ret):
+            raise BadArgument(_("`{arg}` is not a finite number.").format(arg=ret))
+        return ret
+
+
 if TYPE_CHECKING:
     DictConverter = Dict[str, str]
 else: