pattern matching

match.py

def iterate_by_chunk(word, chunk_length):
    i = 0
    while i < len(word):
        yield word[i:i+chunk_length]
        i += chunk_length


def check(word, pattern, len_pattern_word, i_offset):
    """check if the word match the pattern"""
    pattern_length = len(pattern)*len_pattern_word
    corresp = {}
    piece_to_match = word[i_offset:i_offset+pattern_length]
    for i, letter in enumerate(iterate_by_chunk(piece_to_match, len_pattern_word)):
        pattern_letter = pattern[i]
        if pattern_letter in corresp:
            if corresp[pattern_letter] != letter:
                return False,piece_to_match,{}
        else:
            corresp[pattern_letter] = letter
    return True, piece_to_match, corresp

def find_pattern(word, pattern):
    """
    Check if word contain a pattern such as 'aabbcc' or 'abbac' anywhere in the word
    NOTE: Each token have the same length (e.g: if len(a) = 2 then len(b) = 2
    """
    len_pattern_word = 1
    pattern_length = len(pattern)
    while pattern_length < len(word):
        for i in range(0,len(word)-pattern_length+1):
            result, piece, corresp = check(word, pattern, len_pattern_word, i)
            if result:
                print('do match')
                print(piece, corresp)
                return True
        len_pattern_word += 1
        pattern_length = len(pattern)*len_pattern_word
    return False

pattern = 'aabbcc' 
word = '++a-a-b-b-c-c---'
check_pattern(word, pattern)