How Can I Safely Remove List Elements While Iterating in Python?

Removing List Elements During Iteration

When iterating over a Python list, it's common to encounter a scenario where we want to perform actions on each element and subsequently remove them if they meet certain conditions. However, using a straightforward for loop like the one presented in the question can raise concerns, as it violates the "for loop iteration protocol."

To avoid unexpected behavior, an alternative approach is to iterate over a copy of the original list. This allows for safe modifications to the original list while preserving the iteration order:

for item in list(somelist):
  ...
  somelist.remove(item)

By creating a local copy of the list using list(), the for loop iterates over these copies, leaving the original list unmodified. This allows us to freely remove elements from the original list during the iteration without affecting the loop's progress.

Using this technique ensures that the loop will complete without missing any elements and maintains the integrity of both the original list and the iteration process.

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