Question

机器学习的新手我正在尝试使用accuracy score找出线性模型的accuracy_score(y_test,y_pred)。两个变量都已定义。但是出现错误

“未定义名称'y_test'”。

有人可以帮我吗？变量的定义如下：

X_train, X_test, y_train, y_test = train_test_split(x, y, random_state=123)
y_pred = linreg.predict(X_test)

详细错误消息。 NameError跟踪（最近一次通话）在（）中 1＃用于检查准确性和详细信息 2从sklearn.metrics导入precision_score ----> 3 precision_score（y_test，y_pred）

NameError：名称'y_test'未定义

在这里保存代码...

#creating a function for models
from sklearn.model_selection import train_test_split
from sklearn import metrics
#function
def train_test_rmse(x,y):
    x = Iris_data[x]
    y = Iris_data[y]
    X_train, X_test, y_train, y_test = train_test_split(x, y, test_size = 0.2,random_state=123)
    linreg = LinearRegression()
    linreg.fit(X_train, y_train)
    y_pred = linreg.predict(X_test)
    return np.sqrt(metrics.mean_squared_error(y_test, y_pred))

print(train_test_rmse(['Sepal.Length'],['Sepal.Width']))
print(train_test_rmse(['Petal.Length'],['Sepal.Width']))
print(train_test_rmse(['Sepal.Length'],['Petal.Width']))
print(train_test_rmse(['Petal.Length'],['Petal.Width'])) #this one has least rmse
print(train_test_rmse(['Sepal.Width'],['Sepal.Length']))
print(train_test_rmse(['Petal.Width'],['Sepal.Width']))

#for checking the accuracy and details
from sklearn.metrics import accuracy_score
accuracy_score(y_test,y_pred)

Answer 1

您已定义：

X_train, X_test, y_train, y_test = train_test_split(x, y, test_size = 0.2,random_state=123)

在train_test_rmse()函数内部

。这就是为什么这些变量（y_test和y_pred）的作用域仅在函数内部的原因。

不能在函数外部使用它们。

使用以下代码：

from sklearn.model_selection import train_test_split
from sklearn import metrics
from sklearn.metrics import accuracy_score

#function
def train_test_rmse(x,y):
    x = Iris_data[x]
    y = Iris_data[y]
    X_train, X_test, y_train, y_test = train_test_split(x, y, test_size = 0.2,random_state=123)
    linreg = LinearRegression()
    linreg.fit(X_train, y_train)
    y_pred = linreg.predict(X_test)
    print(accuracy_score(y_test, y_pred))  # or you can save it in variable and return it 
    return np.sqrt(metrics.mean_squared_error(y_test, y_pred))

收到错误消息“未定义名称'y_test'”

1 个答案: