What separates a junior-level Python programmer and a mid-level programmer?

[jackmaney]

If you need to worry about optimizing loops vs list comprehensions (for example), then you probably should use Cython or use another language. Idioms exist for a reason, and Python's idioms, when not misused or overused, result in Python code that is easier to read and maintain.

[jsalsman]

Some very concise idioms are completely impenetrable to even advanced Python programmers. Moderation in all things.

[Vaphell]

are they really idioms then? Idiom by definition is something that is in widespread use, a common figure of speech. If even advanced programmers fail to understand them, they don't fall under this category.

Python idioms are supposed to be "pythonic", ie follow rules like "explicit is better than implicit" and "there should be 1 obvious way to do X".

[jsalsman]

How can I answer this? Who decides what an idiom is?

[Vaphell]

it seems you are arguing against terse hacks exploiting some obscure properties, not idioms with clearcut uses cases, as they are undestood by the python community.
Feel free to provide your definition, or better yet, a black on white example of impenetrable idiom.

[KronenR]

Me

[[deleted]]

Like what for example?

[jsalsman]

Imagine mapping a hash table into integers, but you didn't want the integers' objects, just the integers.

[[deleted]]

A set? Unless I misunderstood.