Skip to main content

How to turn pandas dataframe into dictionary?


Introduction

Many times, you will want to search through a dataframe so many times that both writing the search queries using dataframe rules and programmatically the search operation becomes redundant. In such cases, you will want to create a dictionary from a pandas dataframe. Now, if you wonder how, then I have the solution. Read on to explore more.

to_dict() method:

Possible is that you want to turn the rows into values while keeping one specific column as index. In such a case, you have to use the method as follows

df.set_index('id').to_dict()
zip and dict method:

You can use a simpler method and can get done in one line, if your goal is to turn one specific column into keys and one specific column into values, then you can use the zip and dict method. The details follows as below:

data_dict = dict(zip(data[key_column],data[value_column]))
Duplicate document problem:

This is a case when you have multiple values for each key. In that case, it will become a bit custom specific. One thing you can try to do is begin with a groupby and average or aggregate in some other fashion the multiple values occurring for each keys. But, if you seem to lose information in doing so, then you have to address the problem in other fashion. In short, you will open a empty dictionary. then you will populate each key with its associated values into the dictionary as a key-value pair. the related code can be as follows:

keys = list(df[key_column].unique())
my_dict = {}
#now populate
for key in keys:     my_dict[key] = df[df[key_column] == key][value_column].tolist() #done

Conclusion:

These methods will lead to faster dictionary creation and therefore smoother and faster data analysis programs. Hope you enjoyed reading this! For further reading, go through the references: (1) 10 most important pandas functions (2) stackoverflow question which has inspired some of the codes here

Comments

Popular posts from this blog

Mastering SQL for Data Science: Top SQL Interview Questions by Experience Level

Introduction: SQL (Structured Query Language) is a cornerstone of data manipulation and querying in data science. SQL technical rounds are designed to assess a candidate’s ability to work with databases, retrieve, and manipulate data efficiently. This guide provides a comprehensive list of SQL interview questions segmented by experience level—beginner, intermediate, and experienced. For each level, you'll find key questions designed to evaluate the candidate’s proficiency in SQL and their ability to solve data-related problems. The difficulty increases as the experience level rises, and the final section will guide you on how to prepare effectively for these rounds. Beginner (0-2 Years of Experience) At this stage, candidates are expected to know the basics of SQL, common commands, and elementary data manipulation. What is SQL? Explain its importance in data science. Hint: Think about querying, relational databases, and data manipulation. What is the difference between WHERE

What is Bort?

 Introduction: Bort, is the new and more optimized version of BERT; which came out this october from amazon science. I came to know about it today while parsing amazon science's news on facebook about bort. So Bort is the newest addition to the long list of great LM models with extra-ordinary achievements.  Why is Bort important? Bort, is a model of 5.5% effective and 16% total size of the original BERT model; and is 20x faster than BERT, while being able to surpass the BERT model in 20 out of 23 tasks; to quote the abstract of the paper,  ' it obtains performance improvements of between 0 . 3% and 31%, absolute, with respect to BERT-large, on multiple public natural language understanding (NLU) benchmarks. ' So what made this achievement possible? The main idea behind creation of Bort is to go beyond the shallow depth of weight pruning, connection deletion or merely factoring the NN into different matrix factorizations and thus distilling it. While methods like knowle

Spacy errors and their solutions

 Introduction: There are a bunch of errors in spacy, which never makes sense until you get to the depth of it. In this post, we will analyze the attribute error E046 and why it occurs. (1) AttributeError: [E046] Can't retrieve unregistered extension attribute 'tag_name'. Did you forget to call the set_extension method? Let's first understand what the error means on superficial level. There is a tag_name extension in your code. i.e. from a doc object, probably you are calling doc._.tag_name. But spacy suggests to you that probably you forgot to call the set_extension method. So what to do from here? The problem in hand is that your extension is not created where it should have been created. Now in general this means that your pipeline is incorrect at some level.  So how should you solve it? Look into the pipeline of your spacy language object. Chances are that the pipeline component which creates the extension is not included in the pipeline. To check the pipe eleme