Source: 📖 Effective Python item 4

Advanced .format specifier uses

Specifiers (the placeholders between {} symbols) within format strings can be very powerful in some advanced use cases. They can be combined with dictionary and list indexing in the following way:

my_dict = {
	'first_name': 'Juan',
	'surname': 'Coquet',
	}
	
formatted = "My name is {dict['first_name']}. Initals are \
	{dict['fist_name'][0]}{dict['surname'[0]]}.".format(dict=my_dict)

print(formatted)

>>>
My name is Juan. Initials are JC.

See also:

• What is string formatting