Find and replace in xml file with Python

I am really new to Python. I have a xml file with html inside and a csv file.

xml file example:

<example>
  <name id="{{2}}">{{1}}</name>
  <class>{{3}}</class>
    <modules>
      <module>{{4}}</say>
      <module}">{{5}}</say>
      <module>{{6}}</say>
    </modules>
</example>

CSV file with two columns:

1;Alex
2;345
3;10
4;math
5;pysics
6;chemistry

I have to replace values inside {{}} (references are in csv file in first column) with the values in second column of csv file.

I am able to read csv file successfully (No problem with that). I am looking for solution to find and replace in xml file against each {{}}.

I tried

  i=1
  for line in inputfile.readlines():
     outputfile.write(line.replace('{{'+str(i)+'}}', 'value from 2nd colum of csv file'))
     i = i +1 

but it is not replacing all the values.

Thanks in advance.