These are my two dataframes saved in two variables:
> print(df.head()) > club_name tr_jan tr_dec year 0 ADO Den Haag 1368 1422
At first check the type of columns which you want to merge. You will see one of them is string where other one is int. Then convert it to int as following code:
int
df["something"] = df["something"].astype(int) merged = df.merge[df1, on="something"]