title: Find closest lat & lon from large csv
body: <p>I need help using python and pandas. I want to find the ship nearest Lat= 45.82019 and Lon= -129.73671.
  Here is the imported data</p>
  <pre><code>import os
  import pandas as pd
  
  master_df = pd.DataFrame()
  
  for file in os.listdir(os.getcwd()): #combine all csv file
      if file.endswith('.csv'):
          master_df = master_df.append(pd.read_csv(file))
  
  master_df.to_csv('Combined File.CSV', index = False)
  
  df = pd.read_csv('Combined File.CSV')
  print(df)
  </code></pre>
  <p>my data output:
  <a href="https://i.stack.imgur.com/YCwRT.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/YCwRT.png" alt="enter image description here" /></a></p>
  <p>After finding the ship nearest given specific lat&amp;lon, I would like to get all info about that ship.</p>