PrinterErrors.py

# In a factory a printer prints labels for boxes. For one kind of boxes the printer has to use colors which, for the sake of simplicity, are named with letters from a to m.

# The colors used by the printer are recorded in a control string. For example a "good" control string would be aaabbbbhaijjjm meaning that the printer used three times color a, four times color b, one time color h then one time color a...

# Sometimes there are problems: lack of colors, technical malfunction and a "bad" control string is produced e.g. aaaxbbbbyyhwawiwjjjwwm with letters not from a to m.

# You have to write a function printer_error which given a string will return the error rate of the printer as a string representing a rational whose numerator is the number of errors and the denominator the length of the control string. Don't reduce this fraction to a simpler expression.

# The string has a length greater or equal to one and contains only letters from ato z.

def printer_error(s):
    letters=len(s)
    alphabets = "nopqrstuvwxyz"
    string = s.lower()
    count = 0
    for ele in string:
        if ele in alphabets:
            count+=1
    
    return str(count)+"/"+str(letters)