如何将光标移动到 python 中的特定行

Question

我正在从 .txt 文件中读取数据。我需要从某一行开始读取行，所以我不必读取整个文件（使用 .readlines()）。因为我知道我应该从哪一行开始阅读，所以我想到了这个（虽然它不起作用）：

def create_list(pos):
    list_created = []
    with open('text_file.txt', 'r') as f:
        f.seek(pos)          #Here I want to put the cursor at the begining of the line that I need to read from
        line = f.readline()  #And here I read the first line
        while line != '<end>\n':       
            line = line.rstrip('\n')
            list_created.append(line.split(' '))
            line = f.readline()
        f.close()
    return list_created

print(create_list(2))           #Here i need to create a list starting from the 3rd line of my file

我的文本文件看起来像这样：

Something                               #line in pos= 0
<start>                                 #line in pos= 1
MY FIRST LINE                           #line in pos= 2
MY SECOND LINE                          #line in pos= 3
<end>

结果应该类似于：

[['MY', 'FIRST', 'LINE'], ['MY', 'SECOND', 'LINE']]

基本上，我需要从特定行开始我的 readline()。

Answer 1

这个有用吗？如果您不想使用 .readlines() 读取整个文件，您可以通过调用 .readline() 跳过一行。通过这种方式，您可以多次调用 readline() 将光标向下移动，然后 return 下一行。另外，我不建议使用 line != '<end>\n' 除非你绝对确定 <end> 之后会有一个换行符。相反，做类似 not '<end>' in line:

的事情

def create_list(pos):
    list_created = []
    with open('text_file.txt', 'r') as f:
        for i in range(pos):
            f.readline()
        line = f.readline()  #And here I read the first line
        while not '<end>' in line:       
            line = line.rstrip('\n')
            list_created.append(line.split(' '))
            line = f.readline()
        f.close()
    return list_created

print(create_list(2))           #Here i need to create a list starting from the 3rd line of my file

text_file.txt:

Something
<start>
MY FIRST LINE
MY SECOND LINE
<end>

输出：

[['MY', 'FIRST', 'LINE'], ['MY', 'SECOND', 'LINE']]

如何将光标移动到 python 中的特定行

How to move the cursor to a specific line in python

python

text-files

readline