My favorite pandas pattern I work with a lot of transactional timeseries data that includes categories. I often want to create timeseries plots with each category as its own line. This is the method that I use almost data to achieve this result. Typically the data that am working with changes very slowly and trends happen over years not days or weeks. Plotting daily/weekly data tends to be noisy and hides the trend. I use this pattern because it works well with my data and is easy to explain to my stakeholders. Lets Fake some data # Here I am trying to simulate a subset of a large transactional data set. This could be something like sales data, production data, hourly billing, anything that has a date, category, and value. Since we generated this data we know that it is clean. I am still going to assume that it contains some nulls, and an irregular date range. The pattern # Here I am going to take my groupby date and item, this will take care of duplicate entries with the same time sta…