title: Pandas: Find minimum value in a column, write the row containing that column to a new dataframe
body: <p>I have a large number of simple time series in unique CSV files. Each file contains a "Date" column and "Close" column.</p>
  
  <p>I would like to use pandas to read the data for each file into a data frame, find the minimum value in the "Close" column, and write both the minimum "Close" value and associated "Date" to a new dataframe.</p>
  
  <p>This would ideally produce a new dataframe that contains minimum "Close" values and the date on which that minimum occurred, for all files screened.</p>
  
  <pre><code>import pandas as pd
  import os
  
  symbol = "LN"
  start_year = 2010
  end_year = 2014
  months = ["G", "J", "M", "N", "Q", "V", "Z"]
  
  def historiclows():
      df1 = pd.read_csv("%s.csv" % (file3))
      df1 = df1.drop(df1.columns[[1,2,3,5,6]], axis = 1)
      targetvalues = df1.loc[df1["Close"].idxmin()]
      df2.append(targetvalues)
  
  for m in months:
  df2 = pd.DataFrame()    
  
  for y in range(start_year, end_year+1):
      if m != "Z":
          if months[months.index(m)+1] != "Z":
              file1 = ("%s%s%s%s%s%s" % (symbol, m, y, symbol, months[months.index(m)+1], y))
              file2 = ("%s%s%s%s%s%s" % (symbol, months[months.index(m)+1], y, symbol, months[months.index(m)+2], y))
              file3 = ("%s%s" % (file1, file2))
              checkfile3 = os.path.isfile("%s.csv" % file3)
              if checkfile3 == True:
                  title = ("%s%s%s" % (m, months[months.index(m)+1], months[months.index(m)+2]))
                  historiclows()
                  print(df2)
  
              else:
                  pass
  
          else:
              file1 = ("%s%s%s%s%s%s" % (symbol, m, y, symbol, months[months.index(m)+1], y))
              file2 = ("%s%s%s%s%s%s" % (symbol, months[months.index(m)+1], y, symbol, str(months[0]), y+1))
              file3 = ("%s%s" % (file1, file2))
              checkfile3 = os.path.isfile("%s.csv" % file3)
              if checkfile3 == True:
                  title = ("%s%s%s" % (m, months[months.index(m)+1], str(months[0])))
                  historiclows()
                  print(df2)
  
              else:
                  pass
  
      else:
          file1 = ("%s%s%s%s%s%s" % (symbol, m, y, symbol, str(months[0]), y+1))
          file2 = ("%s%s%s%s%s%s" % (symbol, str(months[0]), y+1, symbol, str(months[1]), y+1))
          file3 = ("%s%s" % (file1, file2))
          checkfile3 = os.path.isfile("%s.csv" % file3)
          if checkfile3 == True:
              title = ("%s%s%s" % (m, str(months[0]), str(months[1])))
              historiclows()
              print(df2)
  
          else:
              pass
  </code></pre>
  
  <p>print("!!! PROCESS COMPLETE !!!")</p>