Course Content
Introduction to Python
Introduction to Python
Dictionary Methods
As you've probably noticed, dictionaries have unique characteristics that set them apart from lists and tuples. They also come with their own set of methods. Let's dive in.
len(d)
- returns the number ofkey:value
pairs in the dictionaryd
;d.copy()
- creates a copy of the dictionaryd
;d.items()
- provides all thekey, value
pairs from the dictionaryd
;d.keys()
- lists all the keys in the dictionaryd
;d.values()
- provides all the values from the dictionaryd
.
Wondering how to add new entries to a dictionary? Dictionaries don't utilize list methods like .append()
or .extend()
, and they don't support concatenation like strings. Instead, since dictionaries organize data in key-value pairs, you simply assign values using keys:
d[k] = e
- assigns the value e
to the key k
. If the key k
already exists in the dictionary, its associated value will be updated.
For example, let's add a couple of countries to our dictionary:
# Initial dictionary countries_dict = {'USA': (9629091, 331002651), 'Canada': (9984670, 37742154), 'Germany': (357114, 83783942)} # Update dictionary with two countries countries_dict["Brazil"] = (8515767, 212559417) countries_dict["India"] = (3166391, 1380004385) print(countries_dict)
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