title: Get value from another dataframe column based on condition
body: <p>I have a dataframe like below:</p>
  
  <pre><code>&gt;&gt;&gt; df1
             a   b
  0  [1, 2, 3]  10
  1  [4, 5, 6]  20
  2     [7, 8]  30
  </code></pre>
  
  <p>and another like:</p>
  
  <pre><code>&gt;&gt;&gt; df2
     a
  0  1
  1  2
  2  3
  3  4
  4  5
  </code></pre>
  
  <p>I need to create column 'c' in df2 from column 'b' of df1 if column 'a' value of df2 is in coulmn 'a' df1. In df1 each tuple of column 'a' is a list.</p>
  
  <p>I have tried to implement from following url, but got nothing so far:
  <a href="https://medium.com/@Imaadmkhan1/using-pandas-to-create-a-conditional-column-by-selecting-multiple-columns-in-two-different-b50886fabb7d" rel="nofollow noreferrer">https://medium.com/@Imaadmkhan1/using-pandas-to-create-a-conditional-column-by-selecting-multiple-columns-in-two-different-b50886fabb7d</a></p>
  
  <p>expect result is</p>
  
  <pre><code>&gt;&gt;&gt; df2
     a  c
  0  1 10
  1  2 10
  2  3 10
  3  4 20
  4  5 20
  </code></pre>