How to add multiple key-value pair to Dictionary at once?

Question

I have a dictionary my_dict having some elements like:

my_dict = {
    'India':'Delhi',
    'Canada':'Ottawa',
}

Now I want to add multiple dictionary key-value pair to a dict like:

my_dict = {
    'India': 'Delhi',
    'Canada': 'Ottawa',
    'USA': 'Washington',
    'Brazil': 'Brasilia',
    'Australia': 'Canberra',
}

Is there any possible way to do this? Because I don't want to add elements one after the another.

Answer 1

Use update() method.

d= {'India':'Delhi','Canada':'Ottawa'}
d.update({'USA':'Washington','Brazil':'Brasilia','Australia':'Canberra'})

PS: Naming your dictionary as dict is a horrible idea. It replaces the built in dict.

Answer 2

To make things more interesting in this answer section, you can

add multiple dictionary key-value pair to a dict

by doing so (In Python 3.5 or greater):

d = {'India': 'Delhi', 'Canada': 'Ottawa'}
d = {**d, 'USA': 'Washington', 'Brazil': 'Brasilia', 'Australia': 'Canberra', 'India': 'Blaa'}

Which produces an output:

{'India': 'Blaa', 'Canada': 'Ottawa', 'USA': 'Washington', 'Brazil': 'Brasilia', 'Australia': 'Canberra'}

This alternative doesn't even seem memory inefficient. Which kind-a comes as a contradiction to one of "The Zen of Python" postulates,

There should be one-- and preferably only one --obvious way to do it

What I didn't like about the d.update() alternative are the round brackets, when I skim read and see round brackets, I usually think tuples. Either way, added this answer just to have some fun.

Answer 3

you have a few options:

1. use update():

d= {'India':'Delhi','Canada':'Ottawa'}
d.update({'USA':'Washington','Brazil':'Brasilia','Australia':'Canberra'})

2. use merge:

d= {'India':'Delhi','Canada':'Ottawa'}
d2 = {'USA':'Washington','Brazil':'Brasilia','Australia':'Canberra'}
new_dict = d| d2

Answer 4

The update() method works well

As someone who primarily works in pandas data frames, I wanted to share how you can take values from a data frame and add them to a dictionary using update() and pd.to_dict().

import pandas as pd

Existing dictionary

my_dict = {
        'India':'Delhi',
        'Canada':'Ottawa',
    }

Data frame with additional values you want to add to dictionary

country_index = ['USA','Brazil','Australia']
city_column = ['Washingon','Brasilia','Canberra']
new_values_df = pd.DataFrame(data=city_column, index=country_index, columns=['cities'])

Adding data frame values to dictionary

my_dict.update(new_values_df.to_dict(orient='dict')['cities'])

Dictionary now looks like

my_dict = {
    'India': 'Delhi',
    'Canada': 'Ottawa',
    'USA': 'Washington',
    'Brazil': 'Brasilia',
    'Australia': 'Canberra',
}