Python读下一个()

Question

next()在python中不起作用.在Python中阅读下一行的替代方法是什么？这是一个示例:

filne = "D:/testtube/testdkanimfilternode.txt"
f = open(filne, 'r+')

while 1:
    lines = f.readlines()
    if not lines:
        break
    for line in lines:
        print line
        if (line[:5] == "anim "):
            print 'next() '
            ne = f.next()
            print ' ne ',ne,'\n'
            break

f.close()

在文件上运行此操作不会显示"ne".

Answer 1

执行此操作时:f.readlines()您已经读取了所有文件,因此f.tell()会显示您位于文件末尾,这样做f.next()会导致StopIteration错误.

您想要做的事情的替代方案是:

filne = "D:/testtube/testdkanimfilternode.txt"

with open(filne, 'r+') as f:
    for line in f:
        if line.startswith("anim "):
            print f.next() 
            # Or use next(f, '') to return <empty string> instead of raising a  
            # StopIteration if the last line is also a match.
            break

Answer 2

next()在你的情况下不起作用,因为你第一次调用readlines()哪个基本上设置文件迭代器指向文件的结尾.

既然您正在阅读所有行,您可以使用索引引用下一行:

filne = "in"
with open(filne, 'r+') as f:
    lines = f.readlines()
    for i in range(0, len(lines)):
        line = lines[i]
        print line
        if line[:5] == "anim ":
            ne = lines[i + 1] # you may want to check that i < len(lines)
            print ' ne ',ne,'\n'
            break