Task: Text processing_2
C#: using System;
using System.Collections.Generic;
using System.Text.RegularExpressions;
using System.IO;

namespace TextProc2
{
    class Program
    {
        static void Main(string[] args)
        {
            Regex multiWhite = new Regex(@"\s+");
            Regex dateEx = new Regex(@"^\d{4}-\d{2}-\d{2}$");
            Regex valEx = new Regex(@"^\d+\.{1}\d{3}$");
            Regex flagEx = new Regex(@"^[1-9]{1}$");
            
            int missformcount = 0, totalcount = 0;
            Dictionary<int, string> dates = new Dictionary<int, string>();

            using (StreamReader sr = new StreamReader("readings.txt"))
            {
                string line = sr.ReadLine();
                while (line != null)
                {
                    line = multiWhite.Replace(line, @" ");                    
                    string[] splitLine = line.Split(' ');
                    if (splitLine.Length != 49)
                        missformcount++;
                    if (!dateEx.IsMatch(splitLine[0]))                        
                        missformcount++;                    
                    else
                        dates.Add(totalcount + 1, dateEx.Match(splitLine[0]).ToString());
                    int err = 0;                    
                    for (int i = 1; i < splitLine.Length; i++)
                    {
                        if (i%2 != 0)
                        {
                            if (!valEx.IsMatch(splitLine[i]))                          
                                err++;
                        }
                        else
                        {
                            if (!flagEx.IsMatch(splitLine[i]))
                                err++;                                                        
                        }                        
                    }
                    if (err != 0) missformcount++;
                    line = sr.ReadLine();
                    totalcount++;                    
                }
            }

            int goodEntries = totalcount - missformcount;
            Dictionary<string,List<int>> dateReverse = new Dictionary<string,List<int>>();

            foreach (KeyValuePair<int, string> kvp in dates)
            {
                if (!dateReverse.ContainsKey(kvp.Value))
                    dateReverse[kvp.Value] = new List<int>();
                dateReverse[kvp.Value].Add(kvp.Key);
            }

            Console.WriteLine(goodEntries + " valid Records out of " + totalcount);

            foreach (KeyValuePair<string, List<int>> kvp in dateReverse)
            {
                if (kvp.Value.Count > 1)
                    Console.WriteLine("{0} is duplicated at Lines : {1}", kvp.Key, string.Join(",", kvp.Value));                    
            }
        }
    }
}

Python: import re
import zipfile
import StringIO

def munge2(readings):

   datePat = re.compile(r'\d{4}-\d{2}-\d{2}')
   valuPat = re.compile(r'[-+]?\d+\.\d+')
   statPat = re.compile(r'-?\d+')
   allOk, totalLines = 0, 0
   datestamps = set([])
   for line in readings:
      totalLines += 1
      fields = line.split('\t')
      date = fields[0]
      pairs = [(fields[i],fields[i+1]) for i in range(1,len(fields),2)]

      lineFormatOk = datePat.match(date) and \
         all( valuPat.match(p[0]) for p in pairs ) and \
         all( statPat.match(p[1]) for p in pairs )
      if not lineFormatOk:
         print 'Bad formatting', line
         continue
		
      if len(pairs)!=24 or any( int(p[1]) < 1 for p in pairs ):
         print 'Missing values', line
         continue

      if date in datestamps:
         print 'Duplicate datestamp', line
         continue
      datestamps.add(date)
      allOk += 1

   print 'Lines with all readings: ', allOk
   print 'Total records: ', totalLines



readings = open('readings.txt','r')
munge2(readings)