title: How to create a dummy column from a string expression in pandas data frame?
body: <p>So, I am quite new to python, and this my first ever stack overflow post. </p>
  
  <p>So I have a column in data frame that contains actions in poker hand abbreviated as letters. </p>
  
  <pre><code>pdb_RED.PRFLOP_A.unique()
  array(['BrA', 'Brf', 'Bk', 'f', 'Bc', 'r', 'Bf', 'c', 'B', 'Br', 'cc',
     'Bcf', 'Bcc', 'BcrA', 'Brc', 'BQ', 'Brr', 'rf', 'rc', 'BrQ', 'BcA',
     'cr', 'cf', 'Q', 'fQ', 'BKQ', 'rr', 'BrcA', 'rrc', 'Bcr', 'BcQ',
     'BA', 'rQ', 'BfQ', 'rA', 'KQ', 'rrA'], dtype=object)
  </code></pre>
  
  <p>I want to create a new column in my data frame, that contains dummy variable for 1, if the expression is matched in a column, and 0 for everything else. Expression:</p>
  
  <pre><code>A1_agro=pdb_RED['PRFLOP_A'].str.contains('[bBrA]$', regex=True)
  </code></pre>
  
  <p>It returns a tuple with True/False values. (So 1 for True , 0 for False i need)
  I proceed by creating an empty column in my original data frame, and later follow with an attempt with my limited knowledge. I hope someone can give my directions, because it returns 'tuple' object does not support item assignment' error. </p>
  
  <pre><code>pdb_RED['PRFLOP_agro']=np.nan
  for row in pdb_RED.iterrows():
      if A1_agro[1]==True:
          row['PRFLOP_agro']=1
      else:
          row['PRFLOP_agro']=0
  </code></pre>