exercise10_2.py

#Exercise  10.2: This program counts the distribution of the hour of the day for each of the messages. 
# You can pull the hour from the "From" line by finding
#the time string and then splitting that string into parts using the colon
#character. Once you have accumulated the counts for each hour, print out the
#counts, one per line, sorted by hour as shown below.
#Sample line: From stephen.marquard@uct.ac.az Sat Jan 05 09:14:16 2008
#Sample Execution:
#python timeofday.py
#Enter a file name: mbox-short.txt
#04 3
#06 1
#07 1
#09 2
#10 3
#11 6
#14 1
#15 2
#16 4
#17 2
#18 1
#19 1

dictionary_hours= dict ()                            # Initialize variables 
lst=list ()

fname=input ('Enter file name:')
try:
    fhand=open (fname)
except FileNotFoundError:
    print ('File cannot be found:', fname)           # Try to open the file, and if not possible
    quit ()                                          # Print quit ()
    
for line in fhand:
    words=line.split ()
    if len (words) <5 or words [0] !='From':         # Read the document
        continue     
      
    col_pos=words [5].find (':')                       # Pull the hour position
    hour=words [5][:col_pos]
    if hour not in dictionary_hours:
        dictionary_hours[hour]=1                     # First entry
    else:
        dictionary_hours [hour]+=1                   # Additional counts
for key, val in list (dictionary_hours.items()):
    lst.append ((key,val))                           # Fills list with hour, count of dict
    
lst.sort ()                                          # Sorts by hour

for key, val in lst:
    print (key,val)