Added note for async from filter calls

diff --git a/jinja2/environment.py b/jinja2/environment.py
index 759ecb97ee0bc8267a78d291986fe1772eec14b6..7aa9cef88385c82e7149c67d868d45fc0ae98d7b 100644 (file)
--- a/jinja2/environment.py
+++ b/jinja2/environment.py
@@ -427,6 +427,11 @@ class Environment(object):
                     context=None, eval_ctx=None):
         """Invokes a filter on a value the same way the compiler does it.
 
+        Note that on Python 3 this might return a coroutine in case the
+        filter is running from an environment in async mode and the filter
+        supports async execution.  It's your responsibility to await this
+        if needed.
+
         .. versionadded:: 2.7
         """
         func = self.filters.get(name)