title: How to read a tuple with python pandas and How Series.replace function works
body: <p>I want to read a file with <code>read_table</code>.Every row of the file is a tuple,Like
  <code>('20151130','10',...,'23')</code>. I set <code>dataset = read_table(filename,names = ['date',...,'number'])</code>.And I get <code>dataset['date'] = ('20151130'</code>...</p>
  
  <p>So I want to delete "(" in "('20151130'". But <code>dataset['date'].replace("(","")</code> do not work on every element in dataset['date']. I just use a loop to finish it.</p>
  
  <pre><code>for i in xrange(N):
      dataset_1.append(dataset['date'][i].replace("(",""))
  </code></pre>
  
  <p>How can I read a tuple easily? And why Series.replace can't work on every element  with default?Thank you.</p>