Resolve the problem of removing element newspaper exceptions when Python traverses the dictionary

Wrong code

d = {'a':1, 'b':0, 'c':1, 'd':0}
for key, val in d.items():
  del(d[k])

Error code -- for Python3

d = {'a':1, 'b':0, 'c':1, 'd':0}
for key, val in d.keys():
  del(d[k])

Correct code

d = {'a':1, 'b':0, 'c':1, 'd':0}
keys = list(d.keys())
for key, val in keys:
  del(d[k])