乱码的原因大多数可能都是没有中文字体，或者中文字体不完全，也有可能是编码的问题，如果设置浏览器的编码没有用可以试试我这个方法。

看下故障现象，看的出来下图都是中文自己显示小方框：

Warning: Trying to access array offset on value of type null in /var/www/typecho/usr/plugins/MarkdownParse/ParsedownExtra.php on line 225

Warning: Trying to access array offset on value of type null in /var/www/typecho/usr/plugins/MarkdownParse/ParsedownExtra.php on line 225

Deprecated: preg_match(): Passing null to parameter #2 ($subject) of type string is deprecated in /var/www/typecho/usr/plugins/MarkdownParse/ParsedownExtra.php on line 225

Warning: Trying to access array offset on value of type null in /var/www/typecho/usr/plugins/MarkdownParse/ParsedownExtra.php on line 225

Warning: Trying to access array offset on value of type null in /var/www/typecho/usr/plugins/MarkdownParse/ParsedownExtra.php on line 225

Deprecated: preg_match(): Passing null to parameter #2 ($subject) of type string is deprecated in /var/www/typecho/usr/plugins/MarkdownParse/ParsedownExtra.php on line 225

Warning: Trying to access array offset on value of type null in /var/www/typecho/usr/plugins/MarkdownParse/ParsedownExtra.php on line 225

Warning: Trying to access array offset on value of type null in /var/www/typecho/usr/plugins/MarkdownParse/ParsedownExtra.php on line 225

Deprecated: preg_match(): Passing null to parameter #2 ($subject) of type string is deprecated in /var/www/typecho/usr/plugins/MarkdownParse/ParsedownExtra.php on line 225

Warning: Trying to access array offset on value of type null in /var/www/typecho/usr/plugins/MarkdownParse/ParsedownExtra.php on line 225

Warning: Trying to access array offset on value of type null in /var/www/typecho/usr/plugins/MarkdownParse/ParsedownExtra.php on line 225

Deprecated: preg_match(): Passing null to parameter #2 ($subject) of type string is deprecated in /var/www/typecho/usr/plugins/MarkdownParse/ParsedownExtra.php on line 225

Warning: Trying to access array offset on value of type null in /var/www/typecho/usr/plugins/MarkdownParse/ParsedownExtra.php on line 225

Warning: Trying to access array offset on value of type null in /var/www/typecho/usr/plugins/MarkdownParse/ParsedownExtra.php on line 225

Deprecated: preg_match(): Passing null to parameter #2 ($subject) of type string is deprecated in /var/www/typecho/usr/plugins/MarkdownParse/ParsedownExtra.php on line 225

Warning: Trying to access array offset on value of type null in /var/www/typecho/usr/plugins/MarkdownParse/ParsedownExtra.php on line 225

Warning: Trying to access array offset on value of type null in /var/www/typecho/usr/plugins/MarkdownParse/ParsedownExtra.php on line 225

Deprecated: preg_match(): Passing null to parameter #2 ($subject) of type string is deprecated in /var/www/typecho/usr/plugins/MarkdownParse/ParsedownExtra.php on line 225

python中常见的逻辑运算字符：

and     #与
or      #或
not     #非
!=      #不等于
==      #等于

如题，今天要说的就是这个。以往在windows中不同版本python可以通过设置环境变量重命名python文件来达到不同版本的执行。现在我们可以用powershell的别名设置和自动加载脚本功能来实现不同python版本的执行。