<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def make_env_key(app_name, key):
 """Creates an environment key-equivalent for the given key"""

    key = key.replace('-', '_').replace(' ', '_')
    return str("_".join((x.upper() for x in (app_name, key))))