Question

我正在编写一个程序，该程序在文件中找到某些文本行，并将它们写入另一个文件，以消除其间的所有烦人文本（它是.vmg文件）。通过我的python和googleing技巧，我编写了以下程序。

with open("filein.txt") as f:
    with open("fileout.txt", "w") as f1:
        for line in f:
            if "telephone number" in line:
                f1.write(line)
            if "telephone number" and "X-BOX" in line:
                f1.write(line)
            if "Subject" in line:
                f1.write(line)

该计划工作正常，但对于＆＃34;主题＆＃34;我想告诉程序不仅要编写关键字＆＃34; subject＆＃34;的单行文本。是，但直到它达到某个关键字（在我的情况下是＆＃34; END：VBODY＆＃34;）。我该怎么办？

Answer 1

不是最优雅的，但您可以使用一个标志来指示光标是否位于Subject和END之间：VBODY ::

with open("filein.txt") as f:
    with open("fileout.txt", "w") as f1:
        for line in f:
            if in_subject:
                f1.write(line)
                if "END:VBODY" in line:
                    in_subject = False
            else:
                if "telephone number" in line:
                    f1.write(line)
                if "telephone number" and "X-BOX" in line:
                    f1.write(line)
                if "Subject" in line:
                    in_subject = True
                    f1.write(line)

Answer 2

如果您只需要这个特例，您可以使用简单的状态变量离开。像这样：

inside_subject = False
with open("fileout.txt", "w") as out:
    for line in open("filein.txt", "r"):
        if inside_subject:
            if not "END:VBODY" in line:
                print line
            else:
                inside_subject = False
        else:
            if "telephone number" in line:
                out.write(line)
            elif "telephone number" in line and "X-BOX" in line: # will never match this though
                out.write(line)
            elif "Subject" in line:
                out.write(line)
                inside_subject = True

虽然如果您有更多条件，请考虑使用某个状态机。

Answer 3

if "Subject" in line:
    f1.write(line[:line.index("END:VBODY")])

Answer 4

这是另一种工作解决方案，只需在if "Subject" in line条件下添加while循环。

with open("filein.txt") as f:
    with open("fileout.txt", "w") as f1:
        for line in f:
            if "telephone number" in line:
                f1.write(line)
            if "telephone number" and "X-BOX" in line:
                f1.write(line)
            if "Subject" in line:
                f1.write(line)

                # new code added here
                while 'END:VBODY' not in line:
                    line = f.next()
                    f1.write(line)

从一个文件读取并在Python中写入另一个文件

4 个答案: