Python – How to transform columns in Pandas: how to use map and apply This time, I will describe how to use map and apply, which are sometimes used in pandas. pandas is a library for data analysis in Python. pandas has various functions for preprocessing data, manipulating data, etc. This time, I will explain … Continue reading “Python – How to transform columns in Pandas: how to use map and apply”
Python – UNION like SQL in pandas In the business, I often come across cases where data must be obtained directly from the data lake and preprocessed. Therefore, I think there are many opportunities to process large amounts of data with pandas. So, this time, I would like to record the case of UNION like … Continue reading “Python – UNION like SQL in pandas”
Python – INNER/LEFT/RIGHT JOIN like SQL in pandas When in the business, I often come across cases where data must be obtained directly from the data lake and preprocessed. Therefore, I think there are many opportunities to process large amounts of data with pandas. So, this time, I would like to record an INNER/LEFT/RIGHT JOIN … Continue reading “Python – INNER/LEFT/RIGHT JOIN like SQL in pandas”
Python – List string with pandas groupby If you are doing business, you may have to acquire data directly from the data lake. Therefore, I think there are many opportunities to process large amounts of data with pandas for preprocessing. So, this time, although it is used less frequently, I would like to record a … Continue reading “Python – List string with pandas groupby”
Python – read csv, tsv, excel files with pandas I will focus on data input and output using pandas here, but there are many other libraries that can help you read and write data in various file formats. Inputs and outputs generally fall into several broad categories. Patterns for reading text files or more efficiently … Continue reading “Python – read csv, tsv, excel files with pandas”