'str' object has no attribute 'match_key' when sorting dictionary

Question

Full error: 'str' object has no attribute 'match_key'

I am trying to sort a dictionary by the values of one of the keys in the objects but I am running into errors whem doing so. What is the best way to do this kind of sort?

Code:

#part of loop

x = {
    'id': f'{item.id}',
    'post': item,
    'match_key': match_percentage

}

temp_dict.update(x)

sorted_dict = sorted(temp_dict, key=operator.attrgetter('match_key'))

Answer 1

If you're looking to sort a list of dictionaries by key, you'll want to use operator.itemgetter instead like this:

from operator import itemgetter

xs = [
    { 'item': "Apple", 'match_key': 20 },
    { 'item': "Grape", 'match_key': 10 },
    { 'item': "Lemon", 'match_key': 50 }]

sorted_dict = sorted(xs, key=itemgetter('match_key'))

print(sorted_dict)
# [{'item': 'Grape', 'match_key': 10},
#  {'item': 'Apple', 'match_key': 20}, 
#  {'item': 'Lemon', 'match_key': 50}]

Explanation

dictionaries represent collections of items. So values stored in dictionaries are considered items, not attributes. This makes sense when we think about how we access values in dictionaries. You use bracket notation [] to access items in a collection, whether by index position or key. But cannot use the dot operator . to retrieve dictionary values by key, because they are not stored as attributes on the dict.

Further Reading

• How do I sort a list of dictionaries by a value of the dictionary?
• Sorting a list of dictionary values by date in python
• Setup element getter for dictionaries