How do I join two DataFrames in pandas?

How do I join two DataFrames in pandas?

You can use the merge() function to join two DataFrames. What type of join do you need: inner, outer, left, or right?

I need to perform a left join.

You can do that by using pd.merge(df1, df2, how='left', on='key_column'). Replace df1, df2, and key_column with your DataFrames and the column you want to join on.

What if the key columns have different names?

In that case, you can specify the left and right key columns using left_on and right_on parameters like this: pd.merge(df1, df2, how='left', left_on='key1', right_on='key2').

Can I join on multiple columns?

Yes, you can join on multiple columns by passing a list to on, left_on, or right_on. For example: pd.merge(df1, df2, how='left', on=['key1', 'key2']).