Codewars note:Printer Error

Exercise:

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.

Examples:

s="aaabbbbhaijjjm"
printer_error(s) => "0/14"

s="aaaxbbbbyyhwawiwjjjwwm"
printer_error(s) => "8/22"

Solution:

import string
def printer_error(s):
    char = 0
    for i in s:
        if i in string.ascii_lowercase[0:13]:
            pass
        else:
            char += 1
    return '%s/%s' % (char, len(s))

 
2.

def printer_error(s):
    return "{}/{}".format(len([x for x in s if x not in "abcdefghijklm"]), len(s))
   

 

string模块 ascii_lowercase