Check for Decimal is in_valid_sample_rate (#1672)

sentry_sdk/tracing_utils.py

@@ -4,6 +4,7 @@
 import math
 
 from numbers import Real
+from decimal import Decimal
 
 import sentry_sdk
 from sentry_sdk.consts import OP
@@ -131,8 +132,8 @@ def is_valid_sample_rate(rate):
 
     # both booleans and NaN are instances of Real, so a) checking for Real
     # checks for the possibility of a boolean also, and b) we have to check
-    # separately for NaN
-    if not isinstance(rate, Real) or math.isnan(rate):
+    # separately for NaN and Decimal does not derive from Real so need to check that too
+    if not isinstance(rate, (Real, Decimal)) or math.isnan(rate):
         logger.warning(
             "[Tracing] Given sample rate is invalid. Sample rate must be a boolean or a number between 0 and 1. Got {rate} of type {type}.".format(
                 rate=rate, type=type(rate)