title: Detect specific sequence of string in a column from a list
body: <p>I'm trying to extract out specific strings using a list. Would that be possible in Python?</p>
  
  <p>I have this list here: </p>
  
  <pre><code>currency = ['SGD', 'GBP', 'USD', 'EUR']
  </code></pre>
  
  <p>And if any of these strings appear in a column, I would want a new column to be created with the respective currency. This is my intended ouput: </p>
  
  <p><strong>Intended Output</strong></p>
  
  <pre><code>Name         Currency        Currency_updated    
  0   Tom    RANDOM_SGD_2017         SGD
  1   nick    TEST_EUR_1381          EUR
  2   krish   FORFUN GBP             GBP
  3   jack    NAs                    &lt;blank&gt;
  </code></pre>
  
  <p><strong>Reproducible Example</strong></p>
  
  <pre><code>import pandas as pd 
  
  data = {'Name':['Tom', 'nick', 'krish', 'jack'], 'Currency':['RANDOM_SGD_2017', 'TEST_EUR_1381', 'FORFUN GBP', 'NAs']} 
  
  df = pd.DataFrame(data) 
  </code></pre>
  
  <p><strong>Dataframe Used</strong></p>
  
  <pre><code>     Name       Currency
  0   Tom RANDOM_SGD_2017
  1   nick    TEST_EUR_1381
  2   krish   FORFUN GBP
  3   jack    NAs
  </code></pre>