import glob
import pathlib as p


# set the path to directory
my_path = 'C:/Users/**/*.bleu'
new_dict = {}
# match files in given directory
for name in glob.glob(my_path, recursive=True):
    # for each file in directory set it's path and open the file
    path_to_file = p.Path(name)
    with path_to_file.open() as f:
        # read 1st line in each file
        line = f.readline()
        # split this line using ',' as separator
        line_splitted = line.split(',')
        # in this case BLUE = YY.YY is the first element of the list,
        # now we have to split it by ' ' and add it to dictionary
        # which key will be the file name and value will be that value
        for i, j in enumerate(line_splitted):
            if i == 0:
                blue_splitted = j.split(' ')
                second_element = float(blue_splitted[2])
                # in that case searched value is on 3rd position (2nd list element)
                new_dict.update({path_to_file: second_element})
print(new_dict)
# find max key (path) searching by values
maximum = max(new_dict, key=new_dict.get)
print(maximum)