Python 将值从函数追加到列表

我使用此功能：

from sklearn.datasets import load_iris
from sklearn.linear_model import LogisticRegression

X, y = load_iris(return_X_y=True)

for i in range(X.shape[1]):
    clf = LogisticRegression(random_state=0, verbose=0, max_iter=1000).fit(X[:,i].reshape(-1,1), y)
    print(clf.score(X[:,i].reshape(-1,1),y))
    

我得到4个值作为输出：

0.7466666666666667
0.5533333333333333
0.9533333333333334
0.96

但当我尝试将这4个值添加到列表中时：

from sklearn.datasets import load_iris
from sklearn.linear_model import LogisticRegression

X, y = load_iris(return_X_y=True)

for i in range(X.shape[1]):
    my_list = []
    clf = LogisticRegression(random_state=0, verbose=0, max_iter=1000).fit(X[:,i].reshape(-1,1), y)
    my_list .append(clf.score(X[:,i].reshape(-1,1),y))

print(my_list)

我只得到最后一个值：

[0.96]

我想得到：

[0.7466666666666667, 0.5533333333333333, 0.9533333333333334, 0.96]

[0.7466666666666667, 0.5533333333333333, 0.9533333333333334, 0.96]

---

我该怎么做呢？

确保在循环之外声明列表，这样它就不会被重置

my_list = []
for i in range(X.shape[1]):
    # you were resetting the list each time
    clf = LogisticRegression(random_state=0, verbose=0, max_iter=1000).fit(X[:,i].reshape(-1,1), y)
    my_list .append(clf.score(X[:,i].reshape(-1,1),y))

您还可以使用列表理解来避免混淆：

my_list = [LogisticRegression(random_state=0, verbose=0, max_iter=1000).fit(X[:,i].reshape(-1,1), y).score(X[:,i].reshape(-1,1),y) for i in range(X.shape[1])]

两者都存储列表：

---

确保在循环之外声明列表，这样它就不会被重置

my_list = []
for i in range(X.shape[1]):
    # you were resetting the list each time
    clf = LogisticRegression(random_state=0, verbose=0, max_iter=1000).fit(X[:,i].reshape(-1,1), y)
    my_list .append(clf.score(X[:,i].reshape(-1,1),y))

您还可以使用列表理解来避免混淆：

my_list = [LogisticRegression(random_state=0, verbose=0, max_iter=1000).fit(X[:,i].reshape(-1,1), y).score(X[:,i].reshape(-1,1),y) for i in range(X.shape[1])]

两者都存储列表：