Первая задача
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from nltk.tokenize import sent_tokenize
from nltk import FreqDist
import pymystem3
import re

f = open('text', 'r')
text = f.read()

words = pymystem3.Mystem().analyze(text)
names = []

for word in words:
    if word.get('analysis'):
        for an in word['analysis']:
            if 'S,имя,жен' in an['gr']:
                names += [an['lex']]
                break


print(w_names)
print(FreqDist(w_names))


Вторая задача
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import re

string =  'AA001A777'

letters = 'ABCEKMHOPTXY'

def check(numb):
    if re.match('^[%s]{1}[0-9]{2}[1-9]{1}[%s]{2}[1-9]?[0-9]{1}[1-9]{1}$' % (letters, letters), numb):
        return 'gen'
    elif re.match('^[%s]{2}[0-9]{2}[1-9]{1}[%s]{1}[1-9]?[0-9]{1}[1-9]{1}$' % (letters, letters), numb):
        return 'tr'
    else:
        return 'incorrect'

print(check(string))