I have an error running docker container, i don't have much experience using Docker and redis that is why i open this issue to ask for help

Traceback (most recent call last):
File "/usr/local/lib/python3.5/site-packages/redis/connection.py", line 439, in connect
sock = self._connect()
File "/usr/local/lib/python3.5/site-packages/redis/connection.py", line 464, in _connect
socket.SOCK_STREAM):
File "/usr/local/lib/python3.5/socket.py", line 733, in getaddrinfo
for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
socket.gaierror: [Errno -2] Name or service not known

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/usr/local/lib/python3.5/site-packages/redis/client.py", line 572, in execute_command
connection.send_command(*args)
File "/usr/local/lib/python3.5/site-packages/redis/connection.py", line 563, in send_command
self.send_packed_command(self.pack_command(*args))
File "/usr/local/lib/python3.5/site-packages/redis/connection.py", line 538, in send_packed_command
self.connect()
File "/usr/local/lib/python3.5/site-packages/redis/connection.py", line 442, in connect
raise ConnectionError(self._error_message(e))
redis.exceptions.ConnectionError: Error -2 connecting to redis:6379. Name or service not known.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/usr/local/lib/python3.5/site-packages/redis/connection.py", line 439, in connect
sock = self._connect()
File "/usr/local/lib/python3.5/site-packages/redis/connection.py", line 464, in _connect
socket.SOCK_STREAM):
File "/usr/local/lib/python3.5/socket.py", line 733, in getaddrinfo
for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
socket.gaierror: [Errno -2] Name or service not known

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "app.py", line 7, in
cache.set(default_key, "one")
File "/usr/local/lib/python3.5/site-packages/redis/client.py", line 1072, in set
return self.execute_command('SET', *pieces)
File "/usr/local/lib/python3.5/site-packages/redis/client.py", line 578, in execute_command
connection.send_command(*args)
File "/usr/local/lib/python3.5/site-packages/redis/connection.py", line 563, in send_command
self.send_packed_command(self.pack_command(*args))
File "/usr/local/lib/python3.5/site-packages/redis/connection.py", line 538, in send_packed_command
self.connect()
File "/usr/local/lib/python3.5/site-packages/redis/connection.py", line 442, in connect
raise ConnectionError(self._error_message(e))
redis.exceptions.ConnectionError: Error -2 connecting to redis:6379. Name or service not known.