#Sort a list of dictionaries python how to
#Sort a list of dictionaries python code

This tutorial illustrates how to sort a list of dictionaries in Python. Lists can also store other objects, like dictionaries that contain key-value pairs. Another condition for this is for that key to be common in all the dictionaries in the list. Use the sort () Function to Sort a List of Dictionaries in Python A list is a linear collection object in Python that can emulate arrays by storing every element at a particular index. We can sort a list based on the key’s value. However, it is not simple to compare dictionary instances using the comparison operator we need to use the key parameter. We can get an advantage by using the sorted() function to sort the list of dictionaries. In this article we will discuss how we can sort a dictionary. We can also specify a key parameter that provides a function to decide the order of the elements. Sort function is one such function for a dictionary in python. It can sort the list in ascending or descending order. This function takes an existing list and returns a sorted list. Use the sorted() Function to Sort a List of Dictionaries in Python

#Sort a list of dictionaries python code

Use the sort() Function to Sort a List of Dictionaries in PythonĪ list is a linear collection object in Python that can emulate arrays by storing every element at a particular index. How to Sort a List of Dictionaries in Python: Sort and Sorted Written by Jeremy Grifski in Code Last Updated You may recall that I recently published an article on parsing a spreadsheet, and the output ended up being a list of dictionaries.Use the sorted() Function to Sort a List of Dictionaries in Python.Or, as the Python interpreter reports: Traceback (most recent call last):Ĭsv_mapping_list.sort(key=lambda item: item.get('Age'))Ĭsv_mapping_list = sorted(csv_mapping_list, key=lambda item: item.get('Age'))Īs usual, I appreciate your support. Here, we have to specify the key parameter as dictionaries cannot be naturally sorted. csv_mapping_list.sort(key=lambda item: item.get('Age')) In the following snippet, we sort the list of dictionaries by age. Instead, we can use the builtin sort function for lists. Luckily for us, we don’t have to implement sorting by hand in Python. Pretty cool stuff! Sorting a List of Dictionaries With Sort Function In other words, we create a tuple on the right side of the expression and unpack it on the left side of the expression. To accomplish the swap, we leverage tuple packing and unpacking. Since looking into this topic, I’ve found that Python has a nice way of handling the variable swap in a single line of code: size = len(csv_mapping_list)Ĭsv_mapping_list, csv_mapping_list = csv_mapping_list, csv_mapping_listĬlearly, I didn’t pick that great of a variable name for the swap, but you get the idea. To do that, we leverage the “Age” field of each dictionary as seen in line 5. Here, we’ve sorted the list of dictionaries in place by age. If csv_mapping_list > csv_mapping_list:Ĭsv_mapping_list = csv_mapping_list Instead, we’ll leverage one of the more popular algorithms, selection sort: size = len(csv_mapping_list) Sorting is probably one of the most researched areas of Computer Science, so we won’t dive into the philosophy. It’s normal for me to share a brute force method followed by a couple more elegant methods, so take care to skip ahead if needed. SolutionsĪs always, I like to share many possible solutions. Today, I want to focus on sorting a list of dictionaries. In any case, we always have to start with data processing. For instance, maybe older individuals prefer certain colors, or perhaps younger individuals have certain types of names. python list sorting dictionary Share Follow edited at 23:08 Prune 76. That way we could plot them in order of increasing or decreasing age to see if we could spot any trends. KeyError: 1 Second attempt: import operator result sorted (myAccountsValues, keyitemgetter ('percent')) which fails to sort on percentage. In this case, we might want to order our data points by age. Likewise, order of the data might matter. In other words, we have our data, but we might want to use a subset of it. Of course, having the data in a nice format and actually using that data for visualization are very different problems. As mentioned before, I was working on parsing a CSV file for data visualization, and I ended up getting everything I wanted in the following format: csv_mapping_list = [