Python Dictionary Index
- Access the Keys From a Dictionary Using the Index
- Access the Values From a Dictionary Using the Index in Python
- Access the Key-Value Pairs From a Dictionary Using the Index in Python
Dictionaries are used for storing key-value pairs in Python. In general, we cannot access a dictionary using the index of their elements for other collections like a list or an array.
Before Python 3.7, dictionaries were orderless. Each key-value is given a random order in a dictionary. We can use the OrderedDict()
method from the collections
module in these cases. It preserves the order in which the key-value pairs are added to the dictionary.
In Python 3.7 and up, the dictionaries were made order-preserving by default.
We can access the keys, values, and key-value pairs using the index in such dictionaries where the order is preserved.
Access the Keys From a Dictionary Using the Index
We will use the keys()
method, which returns a collection of the keys. We can use the index to access the required key from this collection after converting it to a list.
Remember to use the list()
function with the keys()
, values()
and items()
function. It is because that they do not return traditional lists and do not allow access to elements using the index.
The following demonstrates this.
d = {}
d["a"] = 0
d["b"] = 1
d["c"] = 2
keys = list(d.keys())
print(keys[1])
Output:
b
When working below Python 3.7, remember to use the OrderedDict()
method to create the required dictionary with its order maintained. For example,
from collections import OrderedDict
d1 = OrderedDict()
d1["a"] = 0
d1["b"] = 1
d1["c"] = 2
keys = list(d1.keys())
print(keys[1])
Output:
b
Access the Values From a Dictionary Using the Index in Python
When we want to return a collection of all the values from a dictionary, we use the values()
function.
d = {}
d["a"] = 0
d["b"] = 1
d["c"] = 2
values = list(d.values())
print(values[1])
Output:
1
Access the Key-Value Pairs From a Dictionary Using the Index in Python
The items()
function returns a collection of all the dictionary’s key-value pairs, with each element stored as a tuple.
The index can be used to access these pairs from the list.
d = {}
d["a"] = 0
d["b"] = 1
d["c"] = 2
values = list(d.items())
print(values[1])
Output:
('b', 1)
Remember to use the OrderedDict()
function with all the methods if your version of Python doesn’t preserve the order of the dictionary.
Manav is a IT Professional who has a lot of experience as a core developer in many live projects. He is an avid learner who enjoys learning new things and sharing his findings whenever possible.
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