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'python检测某个变量是否有定义的方法'

NULL

'python, 变量, 定义, 检测'

'本文实例讲述了python检测某个变量是否有定义的方法。分享给大家供大家参考。具体如下：
第一种方法使用内置函数locals()：
\\’testvar\\’ in locals().keys()
第二种方法使用内置函数dir()：
\\’testvar\\’ in dir()
第三种方法使用内置函数vars()：
va'

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''

'2023-07-31 02:19:31'

'2023-07-31 02:19:31'

'0'

'<p>本文实例讲述了python检测某个变量是否有定义的方法。分享给大家供大家参考。具体如下：</p>
<p>第一种方法使用内置函数locals()：<br />
\\&#8217;testvar\\&#8217;   in   locals().keys()</p>
<p>第二种方法使用内置函数dir()：</p>
<p>\\&#8217;testvar\\&#8217;   in   dir()</p>
<p>第三种方法使用内置函数vars()：</p>
<p>vars().has_key(\\&#8217;testvar\\&#8217;)</p>
<p>测试如下:</p>
<pre class="brush:py;">
#testvar未定义 
In [1]: \\\'testvar\\\' in locals().keys() 
Out[1]: False 
In [2]: \\\'testvar\\\' in dir() 
Out[2]: False 
In [3]: vars().has_key(\\\'testvar\\\') 
Out[3]: False 
#定义testvar 
In [4]: testvar=1 
In [5]: \\\'testvar\\\' in locals().keys() 
Out[5]: True 
In [6]: \\\'testvar\\\' in dir() 
Out[6]: True 
In [7]: vars().has_key(\\\'testvar\\\') 
Out[7]: True 

</pre>
<p>还有使用try&#8230;except&#8230;自己定义的,总之方法很多.</p>
<p>希望本文所述对大家的Python程序设计有所帮助。</p>'

'1690741171'

'1690741171'

'python, 变量, 定义, 检测'

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  'description' => '本文实例讲述了Python实现在matplotlib中两个坐标轴之间画一条直线光标的方法。分享给大家供大家参考。具体如下：
看看下面的例子和效果吧 # -*- coding: utf-8 -*-
from matplotlib.widgets import MultiCursor
from pylab import figure, show, np
t = np.arange(0.0, 2.0,',
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  'description' => '本文实例讲述了python定时检查某个进程是否已经关闭的方法。分享给大家供大家参考。具体如下： import threading
import time
import os
import subprocess
def get_process_count(imagename): p = os.popen(\\\'tasklist /FI \\"IMAGENAME eq %s\\"\\\' % imagename) return p.rea',
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'python检测某个变量是否有定义的方法_程序人生_晓说杂谈'

'python, 变量, 定义, 检测'

'本文实例讲述了python检测某个变量是否有定义的方法。分享给大家供大家参考。具体如下：第一种方法使用内置函数locals()：\\&amp#8217testvar\\&amp#8217 in locals().keys()第二种方法使用内置函数dir()：\\&amp#8217testvar\\&amp#8217 in dir()第三种方法使用内置函数vars()：va'

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      array (
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        'show' => 'show.html',
        'category' => 'category.html',
        'search' => 'search.html',
        'pagesize' => 20,
        'mpagesize' => 20,
      ),
      'seo' => 
      array (
        'list_title' => '[第{page}页{join}]{name}{join}{SITE_NAME}',
        'show_title' => '[第{page}页{join}]{title}{join}{catname}{join}{SITE_NAME}',
      ),
      'getchild' => 0,
      'urlrule' => 1,
      'html' => 0,
      'chtml' => 0,
    ),
    'displayorder' => '0',
    'is_ctable' => '0',
    'pcatpost' => 0,
    'topid' => '9',
    'catids' => 
    array (
      0 => '9',
    ),
    'is_post' => 1,
    'url' => 'https://www.wxx86.cn/zhishi',
    'total' => '请使用count标签查询',
    'field' => 
    array (
    ),
  ),
  10 => 
  array (
    'id' => '10',
    'tid' => '1',
    'pid' => '0',
    'mid' => 'article',
    'pids' => '0',
    'name' => '每日语录',
    'dirname' => 'yulu',
    'pdirname' => '',
    'child' => 0,
    'disabled' => '0',
    'ismain' => 1,
    'childids' => 10,
    'thumb' => '',
    'show' => '1',
    'content' => '',
    'setting' => 
    array (
      'edit' => 1,
      'disabled' => 0,
      'template' => 
      array (
        'list' => 'list.html',
        'show' => 'show.html',
        'category' => 'category.html',
        'search' => 'search.html',
        'pagesize' => 20,
        'mpagesize' => 20,
      ),
      'seo' => 
      array (
        'list_title' => '[第{page}页{join}]{name}{join}{SITE_NAME}',
        'show_title' => '[第{page}页{join}]{title}{join}{catname}{join}{SITE_NAME}',
      ),
      'getchild' => 0,
      'urlrule' => 1,
      'html' => 0,
      'chtml' => 0,
    ),
    'displayorder' => '0',
    'is_ctable' => '0',
    'pcatpost' => 0,
    'topid' => '10',
    'catids' => 
    array (
      0 => '10',
    ),
    'is_post' => 1,
    'url' => 'https://www.wxx86.cn/yulu',
    'total' => '请使用count标签查询',
    'field' => 
    array (
    ),
  ),
)

'/program/43297-[page].html'

''

'https://www.wxx86.cn/program/43297.html'

array (
  'c' => 'show',
  'id' => '43297',
  'm' => 'index',
)