title: Force a x-axis order in a line plot with strings
body: <p>I am trying to make a line plot in which on the x-axis I have strings that correspond to categories, however, I can't seem to sort the x-axis from smallest to largest because I can't seem to force sort of the axis. </p>
  
  <pre><code>d = {'Average_Age': [22, 34, 49, 61], 'Salary_Category': 
     ['[1200, 2000[', '[2000, 6500[', '[6500, 10000[', '[11000, 15000]']}
  
  df = pd.DataFrame(data=d)
  df
  
  test = sns.lineplot(x= 'Salary_Category' , y= 'Average_Age', data = df)
  plt.title('Average Salaries per Age Category')
  plt.xlabel('Salary Category')
  plt.ylabel('Average Age')
  plt.xticks(rotation=45)
  </code></pre>
  
  <p>So this is the plot that I get,  which doesn't make sense since the. salary categories are mixed up. 
     <a href="https://i.stack.imgur.com/jpVFm.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/jpVFm.png" alt="enter image description here"></a></p>
  
  <p>How could I fix this?</p>