title: I can't open a file for writing in python it gives me an error
body: <pre><code>f2=open(&quot;test3&quot;,&quot;r&quot;)
  
  Traceback (most recent call last):
    File &quot;&lt;pyshell#0&gt;&quot;, line 1, in &lt;module&gt;
      f2=open(&quot;test3&quot;,&quot;r&quot;)
  FileNotFoundError: [Errno 2] No such file or directory: 'test3'`
  </code></pre>