not_speshal questions

not_speshal answers

• How to create a new dataframe column with a set of nested IF rules (apply is very slow)
• Raise a string variable as an exception
• Python merge two columns based on condition
• In pandas, how to pivot a dataframe on a categorical series with missing categories?
• How to expand and create the following dataset in Pandas
• Python Pandas aggregate past rows when a condition is met for time series