IDLE未能註冊一個變量。這怎麼可能？

Question

我在Microsoft Windows 7上使用python 2.7.6和IDLE 2.7.6。

IDLE未能註冊一個變量（名爲x5），如下圖所示。這怎麼可能？

---

觸發問題所採取

操作：

1. 以下是已經在我的IDLE控制檯歷史記錄：

   >>> x1 = np.arange(9.0).reshape((3, 3))
>>> x5 = 4

2. 我把光標放在某處x5 = 4

3. 我打ENTER

4. 此份以下：

   >>> x1 = np.arange(9.0).reshape((3, 3))
>>> x5 = 4

5. 複製後，光標會自動放置在x5 = 4結束。我打一次ENTER，希望x5取值4.

6. I型x5檢查的x5值。我得到

   >>> x5
   

   Traceback (most recent call last):
File "<pyshell#118>", line 1, in <module>
x5
NameError: name 'x5' is not defined
   

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基於Blckknght的回答和評論，它看起來就像我複製擺在首位的IDLE控制檯一次（包括>>>）粘貼以下兩行：

x1 = np.arange(9.0).reshape((3, 3)) 
>>> x5 = 4 

其結果是，該行>>> x5 = 4被簡單地忽略，因爲IDLE只關心它看到的第一條python聲明。

---

整個IDLE日誌：

Python 2.7.6 (default, Nov 10 2013, 19:24:24) [MSC v.1500 64 bit (AMD64)] on win32 
Type "copyright", "credits" or "license()" for more information. 
>>> '#' *3 
'###' 
>>> import numpy as np 
>>> a=np.random.random((3, 3)) 
>>> b=np.random.random((3, 3)) 
>>> a 
array([[ 0.92731349, 0.48377097, 0.32175387], 
     [ 0.65061308, 0.72905101, 0.65499733], 
     [ 0.1334612 , 0.4023123 , 0.50179231]]) 
>>> b 
array([[ 0.35232561, 0.77837691, 0.70645223], 
     [ 0.51114669, 0.83303289, 0.78842767], 
     [ 0.51179183, 0.25109079, 0.91229917]]) 
>>> a*b 
array([[ 0.32671629, 0.37655615, 0.22730374], 
     [ 0.33255872, 0.60732347, 0.51641802], 
     [ 0.06830435, 0.10101691, 0.45778471]]) 
>>> a = [[1, 0], [0, 1]] 

>>> b = [[4, 1], [2, 2]] 

>>> a = [[3, 4], [2, 1]] 
>>> a 
[[3, 4], [2, 1]] 
>>> b 
[[4, 1], [2, 2]] 
>>> np.dot(a, b) 

    File "<pyshell#12>", line 1 
    np.dot(a, b) 
^
IndentationError: unexpected indent 
>>> np.dot(a, b) 
array([[20, 11], 
     [10, 4]]) 
>>> a = [[1, 2]] 
>>> a.dot(b) 

Traceback (most recent call last): 
    File "<pyshell#15>", line 1, in <module> 
    a.dot(b) 
AttributeError: 'list' object has no attribute 'dot' 
>>> a = np.array([[1, 2]]) 
>>> a.dot(b) 
array([[8, 5]]) 
>>> a = np.array([[3,4]]) 
>>> b= = np.array([[3,4]]) 
SyntaxError: invalid syntax 
>>> b= np.dot(a, b) 
np.array([[3,4]]) 

>>> a*b 
array([[60, 44]]) 
>>> a 
array([[3, 4]]) 
>>> b 
array([[20, 11]]) 
>>> np.dot(a, b) 

Traceback (most recent call last): 
    File "<pyshell#24>", line 1, in <module> 
    np.dot(a, b) 
ValueError: objects are not aligned 
>>> 
>>> x1 = np.arange(9.0).reshape((3, 3)) 
>>> x2 = np.arange(3.0) 

>>> np.multiply(x1, x2) 

array([[ 0., 1., 4.], 
     [ 0., 4., 10.], 
     [ 0., 7., 16.]]) 
>>> x1 
array([[ 0., 1., 2.], 
     [ 3., 4., 5.], 
     [ 6., 7., 8.]]) 
>>> z2 

Traceback (most recent call last): 
    File "<pyshell#30>", line 1, in <module> 
    z2 
NameError: name 'z2' is not defined 
>>> x2 
array([ 0., 1., 2.]) 
>>> x1 = np.arange(9.0).reshape((3, 3)) 
>>> x2 = np.arange(9.0).reshape((3, 3)) 
>>> np.multiply(x1, x2) 
array([[ 0., 1., 4.], 
     [ 0., 4., 10.], 
     [ 0., 7., 16.]]) 
>>> x1 
array([[ 0., 1., 2.], 
     [ 3., 4., 5.], 
     [ 6., 7., 8.]]) 
>>> x2 
array([ 0., 1., 2.]) 
>>> x2 
array([ 0., 1., 2.]) 
>>> x1 = np.arange(9.0).reshape((3, 3)) 
>>> x2 = np.arange(9.0).reshape((3, 3)) 
>>> x2 
array([ 0., 1., 2.]) 
>>> x1 
array([[ 0., 1., 2.], 
     [ 3., 4., 5.], 
     [ 6., 7., 8.]]) 
>>> x2 
array([ 0., 1., 2.]) 
>>> x1 = np.arange(9.0).reshape((3, 3)) 
>>> x2 = np.arange(9.0).reshape((3, 3)) 
>>> x2 
array([ 0., 1., 2.]) 
>>> x1 = np.arange(9.0).reshape((3, 3)) 
>>> x2 = np.arange(9.0) 
>>> x2 
array([ 0., 1., 2.]) 
>>> x1 = np.arange(9.0).reshape((3, 3)) 
>>> x2 = 3 
>>> x2 
array([ 0., 1., 2.]) 
>>> x1=1 
>>> x1 
1 
>>> x2 = 3 
>>> x2 
3 
>>> x1 = np.arange(9.0).reshape((3, 3)) 
>>> x2 = np.arange(9.0) 
>>> x2 
3 
>>> x1 = np.arange(9.0).reshape((3, 3)) 
>>> x2 = np.arange(9.0) 
>>> x2 
3 
>>> x1 
array([[ 0., 1., 2.], 
     [ 3., 4., 5.], 
     [ 6., 7., 8.]]) 
>>> x1x1 = np.arange(9.0).reshape((3, 3)) 
>>> x2 = np.arange(9.0) 
>>> x1 = np.arange(9.0).reshape((3, 3)) 
>>> x2 = np.arange(9.0) 
>>> x1 = np.arange(9.0).reshape((3, 3)) 

>>> x1 = np.arange(9.0).reshape((3, 3)) 
>>> x3 = np.arange(9.0) 
>>> x3 

Traceback (most recent call last): 
    File "<pyshell#60>", line 1, in <module> 
    x3 
NameError: name 'x3' is not defined 
>>> x1 = np.arange(9.0).reshape((3, 3)) 
>>> x3 = 4 
>>> x3 

Traceback (most recent call last): 
    File "<pyshell#62>", line 1, in <module> 
    x3 
NameError: name 'x3' is not defined 
>>> x1 = np.arange(9.0).reshape((3, 3)) 
>>> x4 = 4 
>>> x4 

Traceback (most recent call last): 
    File "<pyshell#64>", line 1, in <module> 
    x4 
NameError: name 'x4' is not defined 
>>> 
>>> 


>>> 



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>>> 

>>> x1 = np.arange(9.0).reshape((3, 3)) 
>>> x4 = 4 
>>> x4 

Traceback (most recent call last): 
    File "<pyshell#78>", line 1, in <module> 
    x4 
NameError: name 'x4' is not defined 
>>> x4 = 4 
>>> x4 
4 
>>> x1 = np.arange(9.0).reshape((3, 3)) 
>>> x4 = 4 
>>> x1 = np.arange(9.0).reshape((3, 3)) 
>>> x5 = 5 
>>> x1 = np.arange(9.0).reshape((3, 3)) 
>>> x5 = 4 
>>> x5 

Traceback (most recent call last): 
    File "<pyshell#84>", line 1, in <module> 
    x5 
NameError: name 'x5' is not defined 
>>> x1 = np.arange(9.0).reshape((3, 3)) 
>>> x5 = 4 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
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>>> 
>>> 
>>> x1 = np.arange(9.0).reshape((3, 3)) 
>>> x5 = 4 
>>> x1 = np.arange(9.0).reshape((3, 3)) 
>>> x5 = 4 
>>> x5 

Traceback (most recent call last): 
    File "<pyshell#104>", line 1, in <module> 
    x5 
NameError: name 'x5' is not defined 
>>> 

Answer 1

你一次複製多條線路。當Python 2.7版本的IDLE發生這種情況時，它會忽略第一個之後的所有語句。所以你的x5行永遠不會運行，並且該名稱不受任何約束。

您可以看到x5行開始處動畫中的>>>字符的顏色與其他行不同。當他們被複制時，他們像其他輸入的文本一樣黑。當它們是實際提示時，它們是紅色的（至少在默認顏色方案中）。

您可以通過突出顯示一行代碼並按ENTER來僅複製它，而不是它所屬的整個條目來避免此問題。

在Python 3中，在IDLE控制檯（它說SyntaxError: multiple statements found while compiling a single statement）中同時提供多個語句是錯誤的。