Iteration of a nested dictionary in Python 3

Question

Example of dictionary:

    data_noisy = {'P1': {'age': 'eighty two', 'salary': '60196.0', 'suburb': 
                 'Toorak', 'language': 'English'},
                 'P2': {'age': '49', 'salary': '-16945514.0', 'suburb': 'St. 
                 Kilda', 'language': 'Chinese'},
                 'P3': {'age': '54', 'salary': '49775.0', 'suburb': 
                 'Neverland', 'language': 'Italian'}}

Wanted output:

    data_clean = {'P1': {'age': 'None', 'salary': '60196.0', 'suburb': 
                 'Toorak', 'language': 'English'},
                 'P2': {'age': '49', 'salary': 'None', 'suburb': 'St. 
                 Kilda', 'language': 'Chinese'},
                 'P3': {'age': '54', 'salary': '49775.0', 'suburb': 'None', 
                 'language': 'Italian'}}


    MAX_SALARY = 200000

    VALID_SUBURBS = ["Richmond", "Southbank", "Fitzroy",
              "Docklands", "St. Kilda", "Footscray",
              "Hawthorn", "Parkville", "Toorak", "Brunswick",
              "Kensington", "Flemington", "Frankston", "Dandenong",
              "Caulfield", "Collingwood"]

def clean_data(data):

    data_dict = {}
    data_dict = data
    for key, value in data.items():

        for val in value.items():

            age = value['age']
            if not age.isdigit():
                data_dict['age'] = 'None'
            else:
                data_dict['age'] = value['age']

            salary = float(value['salary'])
            if salary < 0 or salary > MAX_SALARY:
                data_dict['salary'] = 'None'
            else:
                data_dict['salary'] = value['salary']

            suburb = value['suburb']
            if suburb not in VALID_SUBURBS:
                data_dict['suburb'] = 'None'
            else:
                data_dict['suburb'] = value['suburb']

    print(data_dict)

I'm wanting to not change the original dictionary so tried to copy it, then iterate to "clean" the data. Seems like I just get a RuntimeError: dictionary changed size during iteration.

Any assistance with syntax etc. with working with these nested dictionaries would be greatly appreciated.

Thanks.

"so tried to copy it". Where did you do that? – Barmar Oct 13 '18 at 16:26 — Barmar, Oct 13 '18 at 16:26

score 1 · Answer 1 · answered Oct 13 '18 at 16:09

Since you don't want to modify the original dicitonary but you are intending to use a copy and modifying that copy, you will need deepcopy.

from copy import deepcopy

data_clean = deepcopy(data_noisy)

for i in data_clean.values():
    if not i['age'].isdigit():
        i['age'] = 'None'
    if float(i['salary']) < 0 or float(i['salary']) > MAX_SALARY:
        i['salary'] = 'None'
    if i['suburb'] not in VALID_SUBURBS:
        i['suburb'] = 'None'

print(data_noisy)
print(data_clean)

{'P1': {'age': 'eighty two', 'salary': '60196.0', 'suburb': 'Toorak', 'language': 'English'}, 'P2': {'age': '49', 'salary': '-16945514.0', 'suburb': 'St. Kilda', 'language': 'Chinese'}, 'P3': {'age': '54', 'salary': '49775.0', 'suburb': 'Neverland', 'language': 'Italian'}}
{'P1': {'age': 'None', 'salary': '60196.0', 'suburb': 'Toorak', 'language': 'English'}, 'P2': {'age': '49', 'salary': 'None', 'suburb': 'St. Kilda', 'language': 'Chinese'}, 'P3': {'age': '54', 'salary': '49775.0', 'suburb': 'None', 'language': 'Italian'}}

Iteration of a nested dictionary in Python 3

1 Answers1