Append key value pair to a dictionary

Question

Is it possible to append key-value pairs to a dictionary?

For example, I want a dictionary like this: a = {4:"Hello", 1:"World"} can that be done using dictionaries? If it can't, is there an alternate data structure that can do that?

I want it ordered in order I add them. In this case, I added the key-value pair 4:"Hello" first.

Avión · Accepted Answer · 2015-12-03T14:04:24.983

2

from collections import OrderedDict
order_dict = OrderedDict()
order_dict[4] = "Hello"
order_dict[3] = "World"
order_dict[5] = "Bah"
print order_dict

Outputs:

OrderedDict([(4, 'Hello'), (3, 'World'), (5, 'Bah')])

Print key and values:

for key, value in order_dict.iteritems() :
    print key, value

Outputs:

4 Hello
3 World
5 Bah

edited Dec 03 '15 at 14:04

answered Dec 03 '15 at 13:58

Avión

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This is probably what I'm looking for. How would I print a single key value pair? Say, the 2 key-value pair? – Dec 03 '15 at 14:01
@stack Check my updated answer. – Avión Dec 03 '15 at 14:04
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@stack - Maybe you could read some documentation or tutorial materials? – TigerhawkT3 Dec 03 '15 at 14:05
@TigerhawkT3 I did. I just wanted the answer to be complete before accepting it. – Dec 03 '15 at 14:09

score 1 · Answer 2 · answered Dec 03 '15 at 13:55

1

Yes it can.

From the module collections, use OrderedDict to get the sequence of adding keys retained.

answered Dec 03 '15 at 13:55

DisappointedByUnaccountableMod

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Write an example that shows how to use an OrderedDict in this case. – pzp Dec 03 '15 at 13:57
Isn't the answer to OP's first question "No"? This answers their second question about what to do instead. – John Coleman Dec 03 '15 at 13:59

score 0 · Answer 3 · edited May 23 '17 at 12:23

0

use collections.OrderedDict to have ordered dictionaries:

>>> from collections import OrderedDict
>>> original = OrderedDict({1:"world"})
>>> new = OrderedDict({4:"hello"})
>>> new.update(original)
>>> new
# OrderedDict([(4, 'hello'), (1, 'World')])

This would work only for additions at front. For insertions at random locations, see Borja's answer

edited May 23 '17 at 12:23

Community

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answered Dec 03 '15 at 14:01

Ayush

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Append key value pair to a dictionary

3 Answers3