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Python Solution

Tomas Skacel
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Tomas Skacel
Python Development Techdegree Graduate 9,172 Points

Original data is being changed even though a copy was made

from data import data

def data_cleaner(arg):
    for dictionary in arg:
        namesplit = dictionary['name'].split(' ')
        dictionary['first name'] = namesplit[0]
        dictionary['last name'] = namesplit[1]
        del(dictionary['name'])
        if dictionary['admin'] == 'False':
            dictionary['admin'] = False
        elif dictionary['admin'] == 'True':
            dictionary['admin'] = True
        dictionary['id'] = int(dictionary['id'])    
    return arg    

data_copy = data.copy()
cleaned_data = data_cleaner(data_copy)

Hello! This was my initial attempt at this challenge. It does what the challenge asked for, but I did notice something strange. The reason I made a copy of data was to preserve a copy of the original. However, if I print data after running my code, data has been changed and is the same as cleaned_data, even though data was never passed into the function. Why is this happening? Is there any way to make this work?

1 Answer

Rachel Johnson
STAFF
Rachel Johnson
Treehouse Teacher

Hey Tomas Skacel , thanks for your question!

The reason that the original is showing changes is because a shallow copy() was used to copy the data. If you want to preserve the original, what we call a "deep" copy, you'll want to use .deepcopy()

From the Python docs:

  • A shallow copy constructs a new compound object and then (to the extent possible) inserts references into it to the objects found in the original.
  • A deep copy constructs a new compound object and then, recursively, inserts copies into it of the objects found in the original.

I hope this helps!