title: python how to write list of lists to file
body: <p>I am trying to write a list of lists of strings to a file. 
  My big list is of the forme:</p>
  
  <pre><code> 1.0 '0:25.0' '1:50.0' '2:131.0' '3:202.0'
   1.0 '0:2.0'  '1:36.0' '2:131.0' '3:188.0'
  -1.0 '0:56.0' '1:53.0' '2:55.0'  '3:58.0'
  -1.0 '0:50.0' '1:51.0' '2:48.0'  '3:55.0'  
   and so on ... 
  </code></pre>
  
  <p>the first column is of type int and the remaining are of type str.</p>
  
  <p>I have tried the following code:</p>
  
  <pre><code>f = open('dataset', 'w')
  for i in range(len(mylist[0]):
       f.write(str(item) for item in mylist[i])
  f.close()
  </code></pre>
  
  <p>But I get the following error:</p>
  
  <pre><code>TypeError: expected a character buffer object
  </code></pre>
  
  <p>the error occured in line 3 of the above code (f.write(...))</p>
  
  <p>EDIT:</p>
  
  <p>I have tried:</p>
  
  <pre><code> with open("train_data.csv", 'w') as f:
       writer = csv.writer(f)
       writer.writerows(listdata)
  </code></pre>
  
  <p>But, surprisingly, for lines starting with -1.0 I only get the 1st 31 elements ( each line (list) contains 362 elements). I have no idea why this is happening.</p>