Your most unpythonic code snippet
I am an experienced developer new to python, and still catching myself writing correct but unpythonic code. I thought it might be enlightening and entertaining to see small examples of python code people have written that in some way clashes with the generally preffered way of doing things. 

I'm interested in code you actually wrote rather than invented examples. Here is one of mine: In code that was expecting a sequence that could be empty or None I had

    if data is not None and len(data) > 0:

I later reduced that to

    if data:

The simpler version allows additional true values like True or 10, but that's ok because the caller made a mistake and will get an exception from the statements within the if.
Your most unpythonic code snippet
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I am an experienced developer new to python, and still catching myself writing correct but unpythonic code. I thought it might be enlightening and entertaining to see small examples of python code people have written that in some way clashes with the generally preffered way of doing things. 

I'm interested in code you actually wrote rather than invented examples. Here is one of mine: In code that was expecting a sequence that could be empty or None I had

    if data is not None and len(data) > 0:

I later reduced that to

    if data:

The simpler version allows additional true values like True or 10, but that's ok because the caller made a mistake and will get an exception from the statements within the if.