python中进行kmp匹配算法代码

Sure! Here's an example code for the KMP algorithm in Python:

def compute_lps(pattern):
    lps = [0] * len(pattern)
    length = 0
    i = 1

    while i < len(pattern):
        if pattern[i] == pattern[length]:
            length += 1
            lps[i] = length
            i += 1
        else:
            if length != 0:
                length = lps[length - 1]
            else:
                lps[i] = 0
                i += 1

    return lps

def kmp(text, pattern):
    lps = compute_lps(pattern)
    i = j = 0
    matches = []

    while i < len(text):
        if text[i] == pattern[j]:
            i += 1
            j += 1

            if j == len(pattern):
                matches.append(i - j)
                j = lps[j - 1]
        else:
            if j != 0:
                j = lps[j - 1]
            else:
                i += 1

    return matches

# Example usage
text = "ABCABCDABABCDABCDABDE"
pattern = "ABCDABD"

matches = kmp(text, pattern)
if len(matches) > 0:
    print("Pattern found at indices:", matches)
else:
    print("Pattern not found.")

This code defines two functions: `compute_lps` and `kmp`. The `compute_lps` function is used to compute the Longest Proper Prefix which is also a Suffix (LPS) array for the given pattern. The `kmp` function performs the actual KMP search on the text using the LPS array.

In the example usage, we search for the pattern "ABCDABD" in the text "ABCABCDABABCDABCDABDE". If a match is found, the indices where the pattern occurs in the text will be printed. Otherwise, it will print "Pattern not found."

Note that this is a basic implementation, and you may need to modify it based on your specific requirements.