Iterating over dictionary yields string values to be split into characters

Question

Set-Up

I create dictionaries in a loop, all containing the same keys but different values.

A part of one of the dictionaries as example,

data = {
        'type': 'An apartment',
        'sublet': 'Indifferent',
       }

At the end of the loop, I append the values of each dictionary data to a 'large' dictionary all_data.

I create all_data = {} before commencement of the loop.

Problem

When I append the values of data to all_data, Python splits the string values of data into characters. E.g.

all_data {
         'type': ['A', 'n', ' ', 'a', 'p', 'a', 'r', 't', 'm', 'e', 'n', 't'],
         'sublet': ['I', 'n', 'd', 'i', 'f', 'f', 'e', 'r', 'e', 'n', 't'],
         }

I append the values via the following code (which I found here),

for key, value in data.items():
     all_data.setdefault(key,[]).extend(value)

How do I obtain,

all_data {
         'type': 'An apartment',
         'sublet': 'Indifferent',
         }

Such that after the loop is finished, I obtain,

all_data {
         'type': 'An apartment', 'A room', 'An apartment',
         'sublet': 'Indifferent', 'Yes', 'Yes'
         }

where order matters.

[here](https://stackoverflow.com/questions/26910708/merging-dictionary-value-lists-in-python) is a nice one-liner! — syntax, Feb 11 '18 at 06:47

score 3 · Accepted Answer · answered Jul 29 '17 at 09:12

3

You should use .append() not .extend().

for key, value in data.items():
    all_data.setdefault(key,[]).append(value)

.extend() extends the list with the given iterable. A string is an iterable of characters, therefore the target list will receive a single character as each item.

answered Jul 29 '17 at 09:12

Bharel

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I'll be damned. Thanks! – LucSpan Jul 29 '17 at 09:17
@LucSpan If this answer solved your question, click on the check-mark. It will mark the question as solved and give reputation to you and the answerer. There is no obligation to do this. – Bharel Jul 29 '17 at 09:32
I know, just had to wait. – LucSpan Jul 29 '17 at 09:37

Iterating over dictionary yields string values to be split into characters

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