"""方法一:通过索引遍历每个值，再通过条件给新增位置赋值"""
for i in df.index:
    if (df.loc[i,'sy']>=5) & (df.loc[i,'assets']>=1000000):
        df.loc[i,'qualifications'] = 'yes'
    else:
        df.loc[i,'qualifications'] = 'no'

"""方法二：通过np的where方法判断赋值"""
df['qualifications'] = np.where((df['sy']>=5) & (df['assets']>=1000000),'yes','no')

"""方法三:用apply方法设置一个函数"""
def f1(d):
    if (d['sy']>=5) & (d['assets']>=1000000):
        return 'yes'
    else:
        return 'no'
df['qualifications'] = df[['sy','assets']].apply(f1,axis=1) # axis = 1是改变传入数据的轴向
df