Сколько раз символы встречаются в строке

def count_patterns(stream: str, pat1: str, pat2: str) -> int:
    pass
 
text_1 = 'a1b2c3d4-TesTTest'
 
count_patterns(text_1, 'abcd', '1234')

import re
 
def count_patterns(stream: str, pat1: str, pat2: str) -> int:
    return len(re.findall(rf'[{pat1}](?=[{pat2}])', stream))
 
text_1 = 'a1b2c3d4-TesTTest'
 
print(count_patterns(text_1, 'abcd', '1234'))

def count_patterns(stream: str, pat1: str, pat2: str) -> int:
    pairs = {''.join((i, j)) for i in pat1 for j in pat2}
    return sum([stream[i:i + 2] in pairs for i in range(len(stream) - 2)])
 
 
text_1 = 'a1b2c3d4-TesTTest'
 
print(count_patterns(text_1, 'abcd', '1234'))

#v1
def count_patterns(stream: str, pat1: str, pat2: str) -> int:
    count = 0
    for i in range(0, len(stream)-1, 2):
        l1, l2 = stream[i], stream[i+1]
        if l1 in pat1 and l2 in pat2 or l1 in pat2 and l2 in pat1:
            count += 1
    return count
 
text_1 = 'a1b2c3d4-TesTTest'
 
print(count_patterns(text_1, 'abcd', '1234'))

#v2
def count_patterns(stream: str, pat1: str, pat2: str) -> int:
    count = 0
    for i in range(0, len(stream)-1, 2):
        l = set(stream[i: i+2])
        if l.intersection(pat1) and l.intersection(pat2):
            count += 1
    return count
 
text_1 = 'a1b2c3d4-TesTTest'
 
print(count_patterns(text_1, 'abcd', '1234'))

def count_patterns(stream: str, pat1: str, pat2: str) -> int:
    pairs = {''.join((i, j)) for i in pat1 for j in pat2}
    return sum([stream[i:i + 2] in pairs for i in range(len(stream))])
 
 
text_1 = 'a1b2c3d4-TesTTest'
 
print(count_patterns(text_1, 'abcd', '1234'))

text_1 = 'a1Wb2c3d4-TesTTest'

# 1.
from itertools import product
 
def count_patterns(stream: str, pat1: str, pat2: str) -> int:
    return sum(stream.count(i) 
            for i in map(''.join,product(pat1,pat2)))
 
 
text_1 = 'a1b2c3d4-TesTTesta2'
print(count_patterns(text_1, 'abcd', '1234'))
 
 
# 2.
def count_patterns(stream: str, pat1: str, pat2: str) -> int:
    count = 0
    for i in range(len(stream)-1):
        if stream[i] in pat1 and stream[i+1] in pat2:
            count += 1
    return count
 
 
text_1 = 'a1b2c3d4-TesTTesta2'
print(count_patterns(text_1, 'abcd', '1234'))