title: How to check if first character in a Python dataframe column is a digit
body: <p>I have some address information in a Python dataframe, and I would like to check if the first character of one of the columns is a digit. I've found similar queries but nothing within a dataframe. I can extract the first character no problem using:</p>
  
  <pre><code>check = df['ADDRESS_LINE_1'].str[0]
  </code></pre>
  
  <p>however if I try </p>
  
  <pre><code>check = df['ADDRESS_LINE_1'].str[0].isdigit()
  </code></pre>
  
  <p>I get the error </p>
  
  <pre><code>'Series' object has no attribute 'isdigit'
  </code></pre>
  
  <p>I can't find an equivalent code to get this to work in a dataframe. I've also tried creating a new column with the check information in, but this results in the same error. Any help is appreciated.</p>