fh_vicky.py

year_input = raw_input('Please enter a 4-digit year: ')
 
mylist = []
with open('F-F_Research_Data_Factors_daily.txt') as fh:
    lines = fh.readlines()
    slicedline = lines[6:-2]
    header = lines[5].split()
 
    for element in slicedline:
        yearstr = element.split()[0]
 
 
 
        print type(year_input), type(yearstr[:4]), yearstr[:4]
        if year_input == yearstr[:4]:
            print 'available factors: {0}'.format(header)  
 
            factor_input = raw_input('please enter a Fama-French factor:  ') 
            factor_index = header.index(factor_input) + 1
            value = element.split()[factor_index]               
            mylist.append(value)
 
 
    if len(mylist) == 0:
        exit('1st arg must be 4-digit year between 1926 and 2012')
            
 
 
    if factor_input in header:
        len_list = len(mylist)
        sumlist = sum([float(y) for y in mylist])
        print '{0} values, avg {1}'.format(len_list,sumlist/len_list)
 
    else:
         print '2nd arg must be one of the four factors {0}'. format(header)