python中的迭代和条件

Question

shipportMD=pd.read_csv('shipportMD.csv')

for importName in shipportMD['importName'].unique():
    if (len(shipportMD['ItemDecision']=='Accepted')>len(shipportMD['ItemDecision']=='Rejected')):
        print (shipportMD['importName'])

我需要为ItemDecision打印importName值，其中'Accepted'值多于'Rejected'

例如：

导入名称：x，y，x，x

项目决策：拒绝，接受，拒绝，接受

所以x有2个被拒绝，1个被接受

Answer 1

可以使用^{}，然后使用布尔掩码：

df = pd.DataFrame({'ID': [1, 1, 1, 1, 2, 2, 2, 2],
                   'Decision': ['Accepted', 'Rejected', 'Rejected', 'Rejected',
                                'Accepted', 'Accepted', 'Rejected', 'Accepted']})

df_ct = pd.crosstab(df['ID'], df['Decision'])

condition = df_ct['Accepted'] > df_ct['Rejected']

res = df_ct[condition].index  
# Int64Index([2], dtype='int64', name='ID')

或者对交叉列表结果执行您选择的计算：

print(df_ct)

Decision  Accepted  Rejected
ID                          
1                1         3
2                3         1