Renaming dictionary keys through a loop problem - python-3.x

Question

I have a column, 'EDU', in my dataframe, df. where I tried to create a dictionary with value_counts(), poe_dict. It looks like this.
edu_m=df['EDU'].sort_values()
poe_dict = edu_m.value_counts(normalize=True).to_dict()
poe_dict
{4: 0.47974705779026877,
3: 0.24588090637625154,
2: 0.172352011241876,
1: 0.10202002459160373}
Now, I'm trying to replace the keys '4,3,2,1' with these strings which I put in a list.
n_keys=["college","more than high school but not college","high school","less than high school"]
If I do each of them individually, this runs ok, giving me the expected result.
In:
poe_dict['college'] = poe_dict.pop(4)
poe_dict['more than high school but not college'] = poe_dict.pop(3)
poe_dict['high school'] = poe_dict.pop(2)
poe_dict['less than high school'] = poe_dict.pop(1)
Out:
{'college': 0.47974705779026877,
'more than high school but not college': 0.24588090637625154,
'high school': 0.172352011241876,
'less than high school': 0.10202002459160373}
however, if I try to do it as a loop, it produces this.
In:
for key, n_key in zip(poe_dict.keys(), n_keys):
poe_dict[n_key] = poe_dict.pop(key)
poe_dict
Out:
{2: 0.172352011241876,
1: 0.10202002459160373,
'high school': 0.47974705779026877,
'less than high school': 0.24588090637625154}
So I dont understand why the loop does not work for keys 2 and 1?
I have tried to debug it as well to see what happens in the loop like this.
In:
for key, n_key in zip(poe_dict.keys(), n_keys):
print (key,n_key)
poe_dict[n_key] = poe_dict.pop(key)
Out:
4 college
3 more than high school but not college
college high school
more than high school but not college less than high school

Answer 1

You loop over the keys of poe_dict in the for loop. However the keys of poe_dict is modified when the statement is poe_dict[n_key] = poe_dict.pop(key) has been run. Therefore, the keys information gets wrong. The correct way is to store the keys of peo_dict into a list list(poe_dict.keys()) and loop over this new list of keys.
poe_dict = {4: 0.47, 3:0.25, 2:0.17, 1:0.10}
n_keys = ['college', 'more than high school but not college','high school', 'less than high school' ]
keylist = list(poe_dict.keys())
for key, n_key in zip(keylist, n_keys):
print (key,n_key)
poe_dict[n_key] = poe_dict.pop(key)
print (poe_dict)
The results will be
{'college': 0.47, 'more than high school but not college': 0.25, 'high school': 0.17, 'less than high school': 0.1}