Requires Python 3.3+

post_iteration_deletion.py

from contextlib import ExitStack

d = {index: str(index) for index in range(100)}

with ExitStack() as stack:
    for key in d:
        if key % 13 == 0:
            stack.callback(d.pop, key)

print(d)

IMHO simpler and good enough in most cases is:

for key in list(d.keys()):
  if key % 13 == 0:
    del d[key]