在列表 B 中查找列表 A 項目模式搜索

Question

我正在使用搜索模式算法在 txt(list) 中查找 pat(list) 項。 這個 function 應該返回列表 txt 的索引值。

def search(pat, txt):
    M = len(pat)
    N = len(txt)
 
    # A loop to slide pat[] one by one */
    for i in range(N - M + 1):
        j = 0
 
        # For current index i, check
        # for pattern match */
        while(j < M):
            if (txt[i + j] != pat[j]):
                break
            j += 1
 
        if (j == M):
            print("Pattern found at index ", i)
 
 
# Driver's Code
txt = ["GA","07","09","07","0H"]
pat = ["GA","09","0H"]
for i in pat:
    for y in txt:
        if i == y:
            if __name__ == '__main__':
            # Function call
            search(pat, txt)

我已經修改了上面的代碼。 但這不起作用。 但是，在原始代碼中，如果提供一項來拍它，它會起作用，如果提供多於一項來拍，它就會崩潰並且不顯示任何內容。 這是原始代碼。

# Python3 program for Naive Pattern
# Searching algorithm
 
 
def search(pat, txt):
    M = len(pat)
    N = len(txt)
 
    # A loop to slide pat[] one by one */
    for i in range(N - M + 1):
        j = 0
 
        # For current index i, check
        # for pattern match */
        while(j < M):
            if (txt[i + j] != pat[j]):
                break
            j += 1
 
        if (j == M):
            print("Pattern found at index ", i)
 
 
# Driver's Code
if __name__ == '__main__':
    txt = ["GA","07","09","07","0H"]
    pat = ["07"]
     
    # Function call
    search(pat, txt)

請提供不止一項來拍（列出）並執行。 我需要這個朴素的搜索模式算法來查找 txt(list) 中的所有 pat(list) 項目並返回索引。 例如

pat = ["GA","09","0H"]

Answer 1

如果要獲取索引和項目：

[list(filter(lambda item: item[1] == pat_item, enumerate(txt)))[0] for pat_item in pat]

• output：

  [(0, 'GA'), (2, '09'), (4, '0H')]

如果您只想獲取索引：

[list(filter(lambda item: item[1] == pat_item, enumerate(txt)))[0][0] for pat_item in pat]

• output：

  [0, 2, 4]

Answer 2

嘗試這個：

indices = []
for x in pat:
    try:
        indices.append(txt.index(x))
    except ValueError:
        pass

txt = ['GA', '07', '09', '07', '0H']和pat = ['GA', '09', '0H'] ：

>>> indices
[0, 2, 4]