>>> from notes import classifica

>>> s="""Informatica\n===========
... Ramon:8.9:9.9:10.0:5.0:6.9
... Rosa:10.0:10.0
... Mireia:8.9:7.9:6.8
... Aleix:5.6:6.5:8.1:4.0:3.0
... Tresa:3.8:2.9
... Enric:7.8:6.9:9.0
... Maria:8.9:9.9:7.0:5.0:6.9
... Roser:10.0:10.0:8.9
... Peret:8.9:7.9:6.8:5.5:5.9:8.8:5.7:9.2
... Joan:5.6:4.5:8.1:4.2"""


>>> with open('notes1.txt', 'w') as g:
... 	 n=g.write(s[:87])

>>> classifica('notes1.txt', 3)
[('Ramon', 8.14), ('Mireia', 7.87)]

>>> classifica('notes1.txt', 1)
[('Rosa', 10.0), ('Ramon', 8.14), ('Mireia', 7.87)]


>>> with open('notes.txt', 'w') as g:
... 	 n=g.write(s)

>>> classifica('notes.txt', 4)
[('Ramon', 8.14), ('Maria', 7.54), ('Peret', 7.34), ('Joan', 5.6), ('Aleix', 5.44)]

>>> classifica('notes.txt', 6)
[('Peret', 7.34)]

>>> classifica('notes.txt', 1)
[('Rosa', 10.0), ('Roser', 9.63), ('Ramon', 8.14), ('Enric', 7.9), ('Mireia', 7.87), ('Maria', 7.54), ('Peret', 7.34), ('Joan', 5.6), ('Aleix', 5.44), ('Tresa', 3.35)]