Related Articles

# Python | Segregating key’s value in list of dictionaries

• Last Updated : 26 Jul, 2019

While working with dictionaries, we may encounter with problem in which we need to segregate all the similar keys’ values together. This kind of problem can occur in web development domain while working with database. Let’s discuss certain ways in which this problem can be solved.

Method #1 : Using generator expression
A generator expression can be used to perform this particular task. In this we take one key at a time and check for the matching keys in all dictionaries. The drawback is that we need to know the key’s in advanced.

Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics.

To begin with, your interview preparations Enhance your Data Structures concepts with the Python DS Course. And to begin with your Machine Learning Journey, join the Machine Learning - Basic Level Course

 `# Python3 code to demonstrate working of``# Segregating key's value in list of dictionaries``# Using generator expression`` ` `# Initialize list``test_list ``=` `[{``'gfg'` `: ``1``, ``'best'` `: ``2``}, {``'gfg'` `: ``4``, ``'best'``: ``5``}]`` ` `# printing original list``print``(``"The original list : "` `+`  `str``(test_list))`` ` `# Using generator expression``# Segregating key's value in list of dictionaries``res ``=` `[``tuple``(sub[``"gfg"``] ``for` `sub ``in` `test_list),``      ``tuple``(sub[``"best"``] ``for` `sub ``in` `test_list)]``     ` `# printing result ``print``(``"Segregated values of keys are : "` `+` `str``(res))`
Output :

The original list : [{‘best’: 2, ‘gfg’: 1}, {‘best’: 5, ‘gfg’: 4}]
Segregated values of keys are : [(1, 4), (2, 5)]

Method #2 : Using `zip() + map() + values()`
The combination of above functions can also perform the similar task in one line. In this, `values()` is used to extract values, `map()` is used to link individual keys with one other and finally `zip()` joins the their corresponding values to single tuple.

 `# Python3 code to demonstrate working of``# Segregating key's value in list of dictionaries``# Using zip() + map() + values()`` ` `# Initialize list``test_list ``=` `[{``'gfg'` `: ``1``, ``'best'` `: ``2``}, {``'gfg'` `: ``4``, ``'best'``: ``5``}]`` ` `# printing original list``print``(``"The original list : "` `+`  `str``(test_list))`` ` `# Using zip() + map() + values()``# Segregating key's value in list of dictionaries``res ``=` `list``(``zip``(``*``map``(``dict``.values, test_list)))``     ` `# printing result ``print``(``"Segregated values of keys are : "` `+` `str``(res))`
Output :

The original list : [{‘best’: 2, ‘gfg’: 1}, {‘best’: 5, ‘gfg’: 4}]
Segregated values of keys are : [(1, 4), (2, 5)]

My Personal Notes arrow_drop_up