title: Python open() requires full path
body: <p>I am writing a script to read a csv file. The csv file and script lies in the same directory. But when I tried to open the file it gives me <code>FileNotFoundError: [Errno 2] No such file or directory: 'zipcodes.csv'</code>. The code I used to read the file is </p>
  
  <pre><code>with open('zipcodes.csv', 'r') as zipcode_file:
      reader = csv.DictReader(zipcode_file)
  </code></pre>
  
  <p>If I give the full path to the file, it will work. Why <code>open()</code> requires full path of the file ?</p>