Adding support to check if an attribute is present or not without having to get the value (#3957)

* Adding support to check if an attribute is present or not without having to get the value.

* - Renaming the method to more appropriate name.

python/tvm/relay/frontend/common.py

@@ -41,6 +41,20 @@ class StrAttrsDict(object):
     def __init__(self, attrs):
         self.attrs = attrs
 
+    def has_attr(self, key):
+        """Checks if a attribute is present in the map.
+
+        Parameters
+        ----------
+        key : str
+            The attribute key
+
+        Returns
+        -------
+        bool : True if the key is present in the attributes else false.
+        """
+        return key in self.attrs
+
     def get_float(self, key, default=RequiredAttr()):
         """Get float attribute
 

tests/python/frontend/test_common.py

+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+from tvm.relay.frontend.common import StrAttrsDict
+
+
+def test_key_is_present():
+    attrs = StrAttrsDict({"a": 1})
+    assert attrs.has_attr("a")
+
+
+def test_key_is_not_present():
+    attrs = StrAttrsDict({"a": 1})
+    assert not attrs.has_attr("b")
+
+
+if __name__ == '__main__':
+    test_key_is_present()
+    test_key_is_present()