fix trainer distributed attributes

[Borda]

What does this PR do?

Fixing typos in exist check...
Fixes #4990

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[codecov]

Codecov Report

Merging #5303 (c618ee0) into release/1.2-dev (2094633) will not change coverage.
The diff coverage is 100%.

@@               Coverage Diff               @@
##           release/1.2-dev   #5303   +/-   ##
===============================================
  Coverage               93%     93%           
===============================================
  Files                  142     142           
  Lines                10028   10028           
===============================================
  Hits                  9307    9307           
  Misses                 721     721           

[carmocca]

Why do we need the is not None checks? == works for None

[Borda]

Why do we need the is not None checks? == works for None

yes, but the enum does not like being compared with None... but let's try it again... 🐰
anyway, it is just a deprecation solution :]

[carmocca]

yes, but the enum does not like being compared with None

Should work:

from enum import Enum

class Foo(Enum):
    BAR = "bar"

print(None == Foo.BAR)  # False
``

[Borda]

Should work:

from enum import Enum

class Foo(Enum):
    BAR = "bar"

print(None == Foo.BAR)  # False
``

yes, just tried in the past commit c618ee0
not sure how it happened that it was crashing in past... :/