Pandas: Speed up merges
Specify the key column of the merge as the index of your dataframes, then join instead of merge
Recent posts
Pandas: Get memory usage of DataFrame with info
Set the configuration option display.memory_usage
Pandas: Groupby Not As Index
Via the as_index parameter
Pandas: Iterating through groups
Accessing the name and DataFrameGroupBy
Pandas: Get rows with max value of group
Via the apply function