Question

我需要弄清楚是否在文本文件中出现另一个短语之前找到某个短语/行。如果找到该短语，则将通过；如果该短语不存在，则将在截断上方添加一行。值得注意的是，该短语也可以在文档的后面出现。

该txt格式的示例如下：

woijwoi

woeioasd
woaije
Is this found
owijefoiawjwfioj
This is the cutoff

asoi w
more text lines
Is this found
aoiw

搜索应从短语“这是截止”开始。截止线在哪条线上是未知的。如果在截止日期之前存在“是否已找到”，则通过。如果没有，我想在截止日期的正上方添加短语“添加行”。到目前为止，我已经尝试过的代码示例，其中所有字符串都已预先定义：

     find = 'Is this found'
     with open(longStr1) as old_file:
        lines = old_file.readlines()
        with open(endfile1, "w") as new_file:
            for num, line in enumerate(lines):
                if "This is the" in line:
                    base_num = num
                for num in range(1, base_num):
                    if not find in line:
                        if line.startswith("This is the"):
                        line = newbasecase + line

我收到“未定义名称'base_num'的错误”，是否有更好的方法来执行此搜索？

Answer 1

这样的事情呢？查找查找索引和截止索引位置，然后循环浏览行列表并检查截止索引，评估是否存在先前的“查找”变量，如果没有，则添加“添加一行”行并结束新文件。

find = "Is this found"
find_index = 0
cutoff = "This is the cutoff" 
cutoff_index = 0

with open(longStr1) as old_file:
    lines = old_file.readlines()
    if find in lines:
        find_index = lines.index(find)
    if cutoff in lines:
        cutoff_index = lines.index(cutoff)
    with open(endfile1, "w") as new_file:
        for num, line in enumerate(lines):
            if cutoff in line:
                if cutoff_index < find_index:
                    new_file.write("Adding a line\n")
                new_file.write(line)
                break
            new_file.write(line)

如何检查是否在txt文件中的某点之前找到了某行？

1 个答案: