import math
  
def LineToList(FileName):
    FileIn = open(FileName, "r")
    DataList = []
    for Line in FileIn:
        Line = Line.rstrip().split("\t")
        DataList.append(Line)
    FileIn.close()
    return DataList
 
def CalculateDistance(Lat1, Lon1, Lat2, Lon2):
  
    Lat1 = float(Lat1)
    Lon1 = float(Lon1)
    Lat2 = float(Lat2)
    Lon2 = float(Lon2)
  
    nDLat = (Lat1 - Lat2) * 0.017453293
    nDLon = (Lon1 - Lon2) * 0.017453293
  
    Lat1 = Lat1 * 0.017453293
    Lat2 = Lat2 * 0.017453293
  
    nA = (math.sin(nDLat/2) ** 2) + math.cos(Lat1) * math.cos(Lat2) * (math.sin(nDLon/2) ** 2 )
    nC = 2 * math.atan2(math.sqrt(nA),math.sqrt( 1 - nA ))
    nD = 6372.797 * nC
  
    return nD
  
def PrintLocation(FileName, dist, Lat, Lon):
  
   #Input:
       #FileName = a file name containing animal location data (str)
       #dist = a distance in kilometres (float)
       #Lat = Latitude (float)
       #Lon = Longitude (float)
   #Output:
       #returns number of animals found in the area (int)
  
    DataList = LineToList("Mammal.txt")
    PrintLocation = 0
    animalList = list()
    for Line in DataList:
        if CalculateDistance(Line[1], Line[2], 51.452884, -0.973906)<=15:
            PrintLocation += 1
    return PrintLocation


var = PrintLocation("Mammal.txt", 15, 51.452884, -0.973906)
print(var)