{"id":1072,"date":"2023-04-18T22:22:00","date_gmt":"2023-04-18T16:52:00","guid":{"rendered":"https:\/\/geekpython.in\/?p=1072"},"modified":"2023-08-15T13:28:51","modified_gmt":"2023-08-15T07:58:51","slug":"access-list-values-within-the-dictionary","status":"publish","type":"post","link":"https:\/\/geekpython.in\/access-list-values-within-the-dictionary","title":{"rendered":"How to Access List Values within the Dictionary in Python"},"content":{"rendered":"\n

The dictionary<\/strong> is a data structure in Python that belongs to the mapping<\/strong> category. When data(key-value) is enclosed by curly({ }<\/code>) braces, we can say it is a dictionary.<\/p>\n\n\n\n

A dictionary has a key<\/strong> that holds a value<\/strong>, also known as a key-value<\/code> pair. Using the dictionary[key]<\/code>, we can get the value assigned to the key<\/code>.<\/p>\n\n\n\n

What if the dictionary contains the values in the form of a list?<\/strong> In this article, we’ll look at all of the different ways to access items from lists within the dictionary.<\/p>\n\n\n\n

<\/a>Sample data<\/h2>\n\n\n\n

Given data contains items in a list as the values of keys within the dictionary. We’ll work with this given data throughout the article.<\/p>\n\n\n\n

\"Sample<\/figure>\n\n\n\n

<\/a>Using Indexing<\/h2>\n\n\n\n

In the following example, we’ve used the indexing method and passed the index<\/strong> along with the key<\/strong> from which the value is to be extracted.<\/p>\n\n\n\n

The convention dict_name[key][index]<\/code> must be used to access the list values from the dictionary.<\/p>\n\n\n\n

# Using indexing\n\n# Accessing list items from the key\nacc_key = my_data['Python dev']\nprint(acc_key)\n# Accessing first list item from the key\nacc_data = my_data['C++ dev'][0]\nprint(acc_data)\n\n# Accessing third list item from the key\nacc_data1 = my_data['PHP dev'][2]\nprint(acc_data1)\n\n# Accessing second list item from the key 'name' from\n# the dictionary 'detail' within the dictionary 'my_data'\nacc_dict_item = my_data['detail']['name'][1]\nprint(acc_dict_item)<\/pre><\/div>\n\n\n\n
Output<\/strong><\/p>\n\n\n\n
['Sachin', 'Aman', 'Siya']\nRishu\nShalini\nSiya<\/pre><\/div>\n\n\n\n
When we accessed only the key<\/code>, we got the entire list, but when we specified the index<\/code> number with the key<\/code>, we got the specific values.<\/p>\n\n\n\n
<\/a>Using slicing<\/h2>\n\n\n\n
It’s the same as the previous method, except instead of specifying the index value, we’ve used the slicing range.<\/p>\n\n\n\n
# Using slicing method\n\n# Accessing list items by skipping 2 steps\nval = my_data['Python dev'][:3:2]\nprint(val)\n\n# Accessing first list item from the end\nval1 = my_data['C++ dev'][-1:]\nprint(val1)\n\n# Accessing list items except the last item\nval2 = my_data['PHP dev'][:-1]\nprint(val2)<\/pre><\/div>\n\n\n\n
Output<\/strong><\/p>\n\n\n\n
['Sachin', 'Siya']\n['Rahul']\n['Abhishek', 'Peter']<\/pre><\/div>\n\n\n\n
<\/a>Using for loop<\/h2>\n\n\n\n
The for loop has been used in the following example to iterate over the values of the list in the dictionary my_data<\/code>.<\/p>\n\n\n\n
# Using for loop\n\n# 1 - Accessing key and values from the dict 'my_data'\nfor key, value in my_data.items():\n    print(key, value)\n\nprint('-'*20)\n\n# 2 - Iterating over list items from each key\nfor key, value in my_data.items():\n    for items in value:\n        print(f'{key} - {items}')\n\nprint('-'*20)\n\n# 3 - Iterating list items from nested dictionary 'detail'\nfor key, value in my_data['detail'].items():\n    for items in value:\n        print(f'{key} - {items}')\n\nprint('-'*20)\n\n# 4 - Accessing list item from individual key\nfor value in my_data['PHP dev']:\n    print(value)<\/pre><\/div>\n\n\n\n
We iterated both keys<\/code> and values<\/code> from the dictionary my_data<\/code> in the first block of code, then the list items from each key<\/code> in the second block, the list items from each key<\/code> within the nested dictionary detail<\/code> in the third block, and the list items of the specific key<\/code> in the last block of code.<\/p>\n\n\n\n
Output<\/strong><\/p>\n\n\n\n
Python dev ['Sachin', 'Aman', 'Siya']\nC++ dev ['Rishu', 'Yashwant', 'Rahul']\nPHP dev ['Abhishek', 'Peter', 'Shalini']\ndetail {'name': ['Sachin', 'Siya'], 'hobby': ['Coding', 'Reading']}\n--------------------\nPython dev - Sachin\nPython dev - Aman\nPython dev - Siya\nC++ dev - Rishu\nC++ dev - Yashwant\nC++ dev - Rahul\nPHP dev - Abhishek\nPHP dev - Peter\nPHP dev - Shalini\ndetail - name\ndetail - hobby\n--------------------\nname - Sachin\nname - Siya\nhobby - Coding\nhobby - Reading\n--------------------\nAbhishek\nPeter\nShalini<\/pre><\/div>\n\n\n\n
<\/a>Using list comprehension<\/h2>\n\n\n\n
The list comprehension technique is used in the following example. It’s the same method as before, but this time we’ve used the for<\/code> loop within the list<\/code>.<\/p>\n\n\n\n
# Using list comprehension\n\n# Accessing list item from the key 'Python dev'\nlst_com = [item for item in my_data['Python dev']]\nprint(lst_com)\n\n# Accessing list item from nested dictionary\nlst_com1 = [item for item in my_data['detail']['name']]\nprint(lst_com1)<\/pre><\/div>\n\n\n\n
Output<\/strong><\/p>\n\n\n\n
['Sachin', 'Aman', 'Siya']\n['Sachin', 'Siya']<\/pre><\/div>\n\n\n\n
<\/a>Using unpacking(*) operator<\/h2>\n\n\n\n
You’ve probably used the asterisk(*<\/code>) operator for multiplication, exponentiation, **kwargs<\/code>, *args<\/code>, and other things, but we’re going to use it as an unpacking operator<\/strong>.<\/p>\n\n\n\n
# Using unpacking operator\n\n# Accessing values from every key\nusing_unpkg_op = [*my_data.values()]\nprint(using_unpkg_op)\nprint('-'*20)\nprint(using_unpkg_op[0])\n\nprint('-'*20)\n\n# Accessing list items from the key 'Python dev'\nusing_unpkg_op = [*my_data.get('Python dev')]\n# Accessing first item from the list\nprint(using_unpkg_op[0])<\/pre><\/div>\n\n\n\n
The expression *my_data.values()<\/code> in the preceding code will return all the values of the keys in the dictionary my_data<\/code>, and once the values are returned, we can specify the index number to access specific data.<\/p>\n\n\n\n
The expression *my_data.get('Python dev')<\/code> returns the values of the key Python dev<\/code>, and through indexing, we can access the list item.<\/p>\n\n\n\n
Output<\/strong><\/p>\n\n\n\n
[['Sachin', 'Aman', 'Siya'], ['Rishu', 'Yashwant', 'Rahul'], ['Abhishek', 'Peter', 'Shalini'], {'name': ['Sachin', 'Siya'], 'hobby': ['Coding', 'Reading']}]\n--------------------\n['Sachin', 'Aman', 'Siya']\n--------------------\nSachin<\/pre><\/div>\n\n\n\n
<\/a>Conclusion<\/h2>\n\n\n\n
In this article, we’ve seen the different methods to access list items within the dictionary. The dictionary we’ve operated on contains the keys with the values as a list and also a nested dictionary.<\/p>\n\n\n\n
We’ve used five methods to access the list items from the dictionary which are as follows:<\/p>\n\n\n\n