In [55]: import pandas as pd equiv = {7001:1, 8001:2, 9001:3} df = pd.DataFrame( {"A": [7001, 8001, 9001]} ) df["B"] = df["A"].map(equiv) print(df) A B 0 7001 1 1 8001 2 2 9001 3 [3 rows x 2 columns]