Dictionary infinite loop is exiting unexpectedly

There is no guarantee that you will iterate over all your dict entries if you mutate it in your loop. From the docs:

Iterating views while adding or deleting entries in the dictionary may
raise a RuntimeError or fail to iterate over all entries.

You could create an “enumerated” infinite loop similar to your initial attempt using itertools.count(). For example:

from itertools import count

for i in count():
    print(i)
    # don't run this without some mechanism to break the loop, i.e.
    # if i == 10:
    #     break

# OUTPUT
# 0
# 1
# 2
# ...and so on