Better exception handling in yaml_dumper

[allyunion]

File "/home/jylee/work/example/venv/lib/python3.7/site-packages/troposphere/init.py", line 762, in to_yaml long_form=long_form) File "/home/jylee/work/example/venv/lib/python3.7/site-packages/cfn_flip/init.py", line 71, in to_yaml return dump_yaml(data, clean_up, long_form) File "/home/jylee/work/example/venv/lib/python3.7/site-packages/cfn_flip/init.py", line 44, in dump_yaml default_flow_style=False File "/home/jylee/work/example/venv/lib/python3.7/site-packages/yaml/init.py", line 290, in dump return dump_all([data], stream, Dumper=Dumper, **kwds) File "/home/jylee/work/example/venv/lib/python3.7/site-packages/yaml/init.py", line 278, in dump_all dumper.represent(data) File "/home/jylee/work/example/venv/lib/python3.7/site-packages/yaml/representer.py", line 27, in represent node = self.represent_data(data) File "/home/jylee/work/example/venv/lib/python3.7/site-packages/yaml/representer.py", line 48, in represent_data node = self.yaml_representers[data_types[0]](self, data) File "/home/jylee/work/example/venv/lib/python3.7/site-packages/cfn_flip/yaml_dumper.py", line 100, in map_representer return dumper.represent_mapping(TAG_MAP, value, flow_style=False) File "/home/jylee/work/example/venv/lib/python3.7/site-packages/yaml/representer.py", line 118, in represent_mapping node_value = self.represent_data(item_value) File "/home/jylee/work/example/venv/lib/python3.7/site-packages/yaml/representer.py", line 48, in represent_data node = self.yaml_representers[data_types[0]](self, data) File "/home/jylee/work/example/venv/lib/python3.7/site-packages/cfn_flip/yaml_dumper.py", line 100, in map_representer return dumper.represent_mapping(TAG_MAP, value, flow_style=False) File "/home/jylee/work/example/venv/lib/python3.7/site-packages/yaml/representer.py", line 118, in represent_mapping node_value = self.represent_data(item_value) File "/home/jylee/work/example/venv/lib/python3.7/site-packages/yaml/representer.py", line 48, in represent_data node = self.yaml_representers[data_types[0]](self, data) File "/home/jylee/work/example/venv/lib/python3.7/site-packages/cfn_flip/yaml_dumper.py", line 100, in map_representer return dumper.represent_mapping(TAG_MAP, value, flow_style=False) File "/home/jylee/work/example/venv/lib/python3.7/site-packages/yaml/representer.py", line 118, in represent_mapping node_value = self.represent_data(item_value) File "/home/jylee/work/example/venv/lib/python3.7/site-packages/yaml/representer.py", line 48, in represent_data node = self.yaml_representers[data_types[0]](self, data) File "/home/jylee/work/example/venv/lib/python3.7/site-packages/cfn_flip/yaml_dumper.py", line 100, in map_representer return dumper.represent_mapping(TAG_MAP, value, flow_style=False) File "/home/jylee/work/example/venv/lib/python3.7/site-packages/yaml/representer.py", line 118, in represent_mapping node_value = self.represent_data(item_value) File "/home/jylee/work/example/venv/lib/python3.7/site-packages/yaml/representer.py", line 48, in represent_data node = self.yaml_representers[data_types[0]](self, data) File "/home/jylee/work/example/venv/lib/python3.7/site-packages/cfn_flip/yaml_dumper.py", line 98, in map_representer return fn_representer(dumper, key[4:], value[key]) File "/home/jylee/work/example/venv/lib/python3.7/site-packages/cfn_flip/yaml_dumper.py", line 73, in fn_representer value = ".".join(value) TypeError: sequence item 0: expected str instance, ODict found

fn_representer could have better exception handling to find out what is causing the error.