How to sort a dataFrame in python pandas by two or more columns?
Suppose I have a dataframe with columns a, b and c, I want to sort the dataframe by column b in ascending order, and by column c in descending order, how do I do this?
data-analysis
Python: pandas merge multiple dataframes
I have diferent dataframes and need to merge them together based on the date column. If I only had two dataframes, I could use df1.merge(df2, on='date'), to do it with three dataframes, I use df1.merge(df2.merge(df3, on='date'), on='date'), however it becomes really complex and unreadable to do it with multiple dataframes.
How do I sum values in a column that match a given condition using pandas?
Suppose I have a column like so: