Question

我想根据两列条件替换列'k'，并在github上找到此代码片段。

这是代码段：

df.loc[(df['column1'] == some_value) & (df['column2'] == some_other_value), ['column_to_change']] = new_value

这是我使用的代码：

def merged_algo_A(cluster_array): 

    rows,labels = readCluster(cluster_array) # reading the test data

    xtest = pd.DataFrame(np.array(rows).reshape(len(rows),11), columns = list("abcdefghijk"))
    ytest = pd.DataFrame(np.array(labels).reshape(len(labels),1),columns = list("l"))

    #print(xtrain['c'])
    xtest['SportYes'] = np.where(xtest['c']<=16897, '200', '400')
    xtest['stateYes'] = np.where(xtest['k']<=62, '200', '400')
    xtest['durYes'] = np.where(xtest['a']<=0.0585, '200', '400')

    xtest.loc[(xtest['SportYes'] == 200) & (xtest['stateYes'] == 200), 'k'] = 3
    print(xtest)

Answer 1

'200'中的'400'和np.where需要更改为200和400才能获得整数：

xtest['SportYes'] = np.where(xtest['c']<=16897, 200, 400)
xtest['stateYes'] = np.where(xtest['k']<=62, 200, 400)
xtest['durYes'] = np.where(xtest['a']<=0.0585, 200, 400)

xtest.loc[(xtest['SportYes'] == 200) & (xtest['stateYes'] == 200), 'k'] = 3
print(xtest)

或者在''语句中将200添加到400和loc，以便string进行比较：

xtest['SportYes'] = np.where(xtest['c']<=16897, '200', '400')
xtest['stateYes'] = np.where(xtest['k']<=62, '200', '400')
xtest['durYes'] = np.where(xtest['a']<=0.0585, '200', '400')

xtest.loc[(xtest['SportYes'] == '200') & (xtest['stateYes'] == '200'), 'k'] = 3
print(xtest)

Answer 2

此问题已解决，以下是解决此问题的代码：

def merged_algo_A(cluster_array): 

    rows,labels = readCluster(cluster_array) # reading the test data

    xtest = pd.DataFrame(np.array(rows).reshape(len(rows),11), columns = list("abcdefghijk"))
    ytest = pd.DataFrame(np.array(labels).reshape(len(labels),1),columns = list("l"))


    xtest['SportYes'] = np.where(xtest['c']<=16897, 'yes', 'no')
    xtest['stateYes'] = np.where(xtest['f']<=62, 'yes', 'no')


    xtest['labels1'] = xtest['j']
    xtest['reallabels'] = ytest

    xtest.loc[(xtest['SportYes'] == 'yes') , ['labels1']] = 3
    xtest.loc[(xtest['SportYes'] == 'no')  , ['labels1']] = 2

    list1 = list(map(int,xtest['labels1']))

    final_preds = list1
    return final_preds

根据两列或更多列中的条件更改pandas中的列值

2 个答案: