如果您的大型文本文件是严格结构良好的(意味着每一行都有相同的长度l)，您可以使用第n行

with open(file) as f:
    f.seek(n*l)
    line = f.readline() 
    last_pos = f.tell()

这只适用于具有相同长度的文件!

f = open(filename, 'r')
totalLines = len(f.readlines())
f.close()
f = open(filename, 'r')

lineno = 1
while lineno < totalLines:
    line = f.readline()

    if lineno == 26:
        doLine26Commmand(line)

    elif lineno == 30:
        doLine30Commmand(line)

    lineno += 1
f.close()

如果要读取的文件很大，并且你不想一次在内存中读取整个文件:

fp = open("file")
for i, line in enumerate(fp):
    if i == 25:
        # 26th line
    elif i == 29:
        # 30th line
    elif i > 29:
        break
fp.close()

注意第n行i == n-1。

在Python 2.6或更高版本中:

with open("file") as fp:
    for i, line in enumerate(fp):
        if i == 25:
            # 26th line
        elif i == 29:
            # 30th line
        elif i > 29:
            break

这是我的2美分，不管它是否值得;)

def indexLines(filename, lines=[2,4,6,8,10,12,3,5,7,1]):
    fp   = open(filename, "r")
    src  = fp.readlines()
    data = [(index, line) for index, line in enumerate(src) if index in lines]
    fp.close()
    return data


# Usage below
filename = "C:\\Your\\Path\\And\\Filename.txt"
for line in indexLines(filename): # using default list, specify your own list of lines otherwise
    print "Line: %s\nData: %s\n" % (line[0], line[1])

打印第3行，

line_number = 3

with open(filename,"r") as file:
current_line = 1
for line in file:
    if current_line == line_number:
        print(file.readline())
        break
    current_line += 1

原作者:Frank Hofmann

你可以用已经有人提到过的语法很简单地做到这一点，但这是迄今为止最简单的方法:

inputFile = open("lineNumbers.txt", "r")
lines = inputFile.readlines()
print (lines[0])
print (lines[2])