def read_flights (f):
    '''This function takes in a file containing daily flights and compiles them
    into a dictionary which they key of the dictionary is the location of the
    airport followed by a list of destinations as value'''
    dict1 = {}
    temp = []
    d = collections.defaultdict(list)
    for line in f:
        k,v = line.split()
        d[k].append(v)
        
    return d
            
print read_flights(open('daily_flights.txt'))

############# MY OUTPUT #####################
defaultdict(<type 'list'>, {'YHZ': ['YOW', 'YYT', 'YMX', 'YQX', 'YQM', 'YDF', 'YYR', 'YYZ', 'YHM'], 'YYT': ['YAY', 'YYZ', 'YAW', 'YQX', 'YDF', 'YYR', 'YHZ'], 'YVR': ['YXX', 'YEG', 'YYC', 'YXC', 'YXD', 'YXE', 'YHZ', 'YHM', 'YMX', 'YCD', 'YOW', 'YPR', 'YXS', 'YYT', 'YYZ', 'YYJ', 'YAV'], 'YEG': ['YZF', 'YVR', 'YYZ', 'YYJ', 'YMX', 'YMM', 'YEV', 'YQU', 'YLW', 'YXX', 'YYC', 'YXE'], 'YYZ': ['YXX', 'YYC', 'YYG', 'YDF', 'YMM', 'YFC', 'YHZ', 'YGK', 'YXU', 'YQM', 'YYB', 'YQB', 'YQR', 'YSJ', 'YYT', 'YZR', 'YXE', 'YAM', 'YSB', 'YQT', 'YTS', 'YVR', 'YYJ', 'YQG', 'YWG', 'YEG']})

########## daily_flights.txt below###########
YEG YZF
YEG YVR
YEG YYZ
YEG YYJ
YEG YMX
YEG YMM
YEG YEV
YEG YQU
YEG YLW
YEG YXX
YEG YYC
YEG YXE
YYT YAY
YYT YYZ
YYT YAW
YYT YQX
YYT YDF
YYT YYR
YYT YHZ
YHZ YOW
YHZ YYT
YHZ YMX
YHZ YQX
YHZ YQM
YHZ YDF
YHZ YYR
YHZ YYZ
YHZ YHM
YYZ YXX
YYZ YYC
YYZ YYG
YYZ YDF
YYZ YMM
YYZ YFC
YYZ YHZ
YYZ YGK
YYZ YXU
YYZ YQM
YYZ YYB
YYZ YQB
YYZ YQR
YYZ YSJ
YYZ YYT
YYZ YZR
YYZ YXE
YYZ YAM
YYZ YSB
YYZ YQT
YYZ YTS
YYZ YVR
YYZ YYJ
YYZ YQG
YYZ YWG
YYZ YEG
YVR YXX
YVR YEG
YVR YYC
YVR YXC
YVR YXD
YVR YXE
YVR YHZ 
YVR YHM
YVR YMX
YVR YCD
YVR YOW
YVR YPR
YVR YXS
YVR YYT
YVR YYZ
YVR YYJ
YVR YAV