Python-如何在给定许多索引的情况下打印列表的值？

例如，我有索引值：

x = [1, 4, 5, 7]

我有一个元素列表：

y = ['this','is','a','very','short','sentence','for','testing']

我想返回值

['is','short','sentence','testing']

当我试图打印时，请说：

y[1]

---

它将很高兴地返回

['is']

。但是，当我执行

打印（y[x]）

时，它将不返回任何内容。如何打印所有这些索引？奖励：然后将它们连接在一起。

这应该可以完成以下工作：

' '.join([y[i] for i in x])

---

这应该可以做到：

' '.join([y[i] for i in x])

---

尝试此列表comp

[y[i]代表x中的i]

>>> y = ['this','is','a','very','short','sentence','for','testing']
>>> x = [1, 4, 5, 7]
>>> [y[i] for i in x]                    # List comprehension to get strings
['is', 'short', 'sentence', 'testing']
>>> ' '.join([y[i] for i in x])          # Join on that for your bonus
'is short sentence testing'

其他方式

>>> list(map(lambda i:y[i], x) )         # Using map
['is', 'short', 'sentence', 'testing']

---

尝试此列表comp

[y[i]代表x中的i]

>>> y = ['this','is','a','very','short','sentence','for','testing']
>>> x = [1, 4, 5, 7]
>>> [y[i] for i in x]                    # List comprehension to get strings
['is', 'short', 'sentence', 'testing']
>>> ' '.join([y[i] for i in x])          # Join on that for your bonus
'is short sentence testing'

其他方式

>>> list(map(lambda i:y[i], x) )         # Using map
['is', 'short', 'sentence', 'testing']

---

您将需要一个for循环来迭代索引列表，然后使用索引轴调整列表

for i in x: #x is your list, i will take the 'value' of the numbers in your list and will be your indexed
    print y[i]

    > is
      short
      sentence
      testing

---

您将需要一个for循环来迭代索引列表，然后使用索引轴调整列表

for i in x: #x is your list, i will take the 'value' of the numbers in your list and will be your indexed
    print y[i]

    > is
      short
      sentence
      testing

---

如果您有

numpy

软件包，您可以这样做

>>> import numpy as np
>>> y = np.array(['this','is','a','very','short','sentence','for','testing'])
>>> x = np.array([1,4,5,7])
>>> print y[x]
['is' 'short' 'sentence' 'testing']

---

如果您有

numpy

软件包，您可以这样做

>>> import numpy as np
>>> y = np.array(['this','is','a','very','short','sentence','for','testing'])
>>> x = np.array([1,4,5,7])
>>> print y[x]
['is' 'short' 'sentence' 'testing']

---

你说加入是什么意思？你说加入是什么意思？