替换所有行中的一个图案，但仅在另一个图案之前

def replace_pattern_before_another(pattern, replacement, target_pattern, data):
    lines = data.split("\n")  # 将文本数据按行分割为列表
    target_line_index = -1  # 另一个图案所在行的索引

    # 查找另一个图案所在行的索引
    for i, line in enumerate(lines):
        if target_pattern in line:
            target_line_index = i
            break

    # 替换所有行中的目标图案，但仅在另一个图案之前
    for i, line in enumerate(lines):
        if i < target_line_index:
            lines[i] = line.replace(pattern, replacement)

    # 拼接替换后的字符串
    replaced_data = "\n".join(lines)

    return replaced_data

# 示例数据
data = """
Line 1: This is the target pattern.
Line 2: This is not the target pattern.
Line 3: This is the target pattern.
Line 4: This is not the target pattern.
Line 5: This is the target pattern.
"""

# 替换图案并仅在另一个图案之前
pattern = "target"
replacement = "new pattern"
target_pattern = "not the target"
replaced_data = replace_pattern_before_another(pattern, replacement, target_pattern, data)

print(replaced_data)

Line 1: This is the new pattern.
Line 2: This is not the target pattern.
Line 3: This is the new pattern.
Line 4: This is not the target pattern.
Line 5: This is the target pattern.