title: how to convert all dot decimal marker in csv files to comma using python?
body: <p>I have multiple csv files. </p>
  
  <p><a href="https://i.stack.imgur.com/hIlYf.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/hIlYf.png" alt="enter image description here"></a></p>
  
  <p>in these files, "dot" used as a decimal marker.</p>
  
  <p><a href="https://i.stack.imgur.com/qfiAz.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/qfiAz.png" alt="enter image description here"></a></p>
  
  <p>I would like to change all dots to commas and then combine all csv files into one csv file. How can I do this in python?</p>