import pandas as pd

pd.set_option('display.width',None)

pd.set_option('display.max_columns',None)

item1 = pd.read_csv('Nowcoder1.csv')

item2 = pd.read_csv('Nowcoder2.csv')

df = pd.merge(item1,item2, on='Nowcoder_ID',how='left')

print(df)