Python-remove duplicate output

[marco.nawijn at colosso.nl]

On Thursday, November 22, 2018 at 12:10:28 AM UTC+1, drvuc... at gmail.com wrote:
> How to remove duplicate lines and store output into one ine
> 
>    reservations = ec.describe_instances().get('Reservations', []) 
> 
>    for reservation in reservations:
>         for instance in reservation['Instances']:
>             tags = {}
>             for tag in instance['Tags']:
>                 tags[tag['Key']] = tag['Value']
>                 if tag['Key'] == 'Name':
>                     name=tag['Value']
> 
>             if not 'Owner' in tags or tags['Owner']=='unknown' or tags['Owner']=='Unknown':
>                 print name
> 
> Current Output:
> 
> aws-opsworks
> 
> aws-opsworks Ansible
> 
> Desired output:
> 
> aws-opsworks Ansible

You can use a set to do the job. Remember that members in the set are unique,
duplicate members are ignored.

Before you start the for loop, create a set:

names = set()

Instead of `print name`, you add the name to the set:

names.add(name)

Note that if name already exists, because members of a set are unique, 
the name is (at least conceptually) ignored.

Once the for loop is completed, you print the remaining names.

print names (Python 2)
or
print(names) (Python 3)

Marco