Ivanon = {'math':4, 'english':4, 'physic':4, 'chemistry':4, 'biology':4}
Netfullin = {'math':5, 'english':4, 'physic':4, 'chemistry':5, 'biology':4}
Pasternak = {'math':5, 'english':4, 'physic':3, 'chemistry':5, 'biology':4}
Lenina = {'math':5, 'english':5, 'physic':5, 'chemistry':5, 'biology':5}

Ivanon = {'math':4, 'english':4, 'physic':4, 'chemistry':4, 'biology':4}
Doe = {'math':5, 'english':5, 'physic':5, 'chemistry':5, 'biology':5}
Mustermann = {'math':5, 'english':5, 'physic':5}
Dvoechnikov = {'math':3, 'english':3, 'physic':3, 'chemistry':3, 'biology':3}

import yaml

with open(filename) as f:
    data = yaml.safe_load(f.read().replace('=',':'))

In [94]: data
Out[94]:
{'Doe': {'biology': 5, 'chemistry': 5, 'english': 5, 'math': 5, 'physic': 5},
 'Dvoechnikov': {'biology': 3,
  'chemistry': 3,
  'english': 3,
  'math': 3,
  'physic': 3},
 'Ivanon': {'biology': 4,
  'chemistry': 4,
  'english': 4,
  'math': 4,
  'physic': 4},
 'Mustermann': {'english': 5, 'math': 5, 'physic': 5}}

[{'Name1':{'subj1':note, 'subj2':note, ...},
 {'Name2':{'subj1':note, 'subj2':note, ...}]

import re
import ast

def parse_line(line):
    name,rest = re.split('s*=s*', line)
    d = ast.literal_eval(rest)
    return {name:d}

filename = r'C:Temp.data774534.txt'

with open(filename) as f:
    data = [parse_line(line) for line in f]

#best_ones =  [n for x in data for n,d in x.items() if all(val == 5 for val in d.values())]
best_ones = [n for x in data for n,d in x.items() if sum(d.values()) == 5*len(d)]
print(best_ones)

['Doe', 'Mustermann']

with open(input_file, 'r') as file:
    for line in file:
        if all([raiting[-1] == '5' for raiting in line[line.index('{') + 1:line.index('}')].split(', ')]):
            print(line[:line.index('=')].strip())

[surname for (surname, _dict) in (line.split('=', 1) for line in filter(str.strip, open('file.txt'))) if all((val == 5) for val in eval(_dict).values())]