Question

我仍在使用python副本并替换行，问题Here。基本上，我想统计一个部分中模式的数量，并在行中更新它。我想我已经在我的问题中找到了问题：我调用一个子函数来对主函数中的同一个文件进行交互，并且交互正在弄乱。我对编程很陌生，我不知道如何以另一种方式做这个copy-statistics-replace-copy的事情。欢迎任何建议或提示。

以下是我现在获得的代码的一部分：

URL url = new URL(
        "https://65.media.tumblr.com/839a07990f2b1ffa32065513c6224493/tumblr_oe6t3aYpHc1qfilt7o1_500.jpg");
String path = url.getPath();
channelSftp.put(url.openStream(),path.substring(path.lastIndexOf('/')+1));

原件：

# sum number of keyframes
def sumKeys (sceneObj, objName):
    sceneObj.seek(0)
    block = []
    Keys = ""
    for line in sceneObj:
        if line.find("ObjectAlias " + objName + "\n") != -1:
            for line in sceneObj:
                if line.find("BeginKeyframe") != -1:
                    for line in sceneObj:
                        if line.find("default") != -1:
                            block.append(line.rstrip())
                            Keys = len(block)
                        elif line.find("EndKeyframe") != -1:
                            break
                    break
            break
    return (Keys)

# renew number of keyframes
def renewKeys (sceneObj, objName):
    sceneObj.seek(0)
    newscene = ""
    item = []
    for line in sceneObj:
        newscene += line
        for obj in objName:
            if line.find("ObjectAlias " + obj + "\n") != -1:
                for line in sceneObj:
                    if line.find("EndKeyframe") != -1:
                        newscene += line
                        break
                    if line.find("BeginKeyframe") != -1:
                        item = line.split()
                        newscene += item[0] + " " + str(sumKey(sceneObj, obj)) + " " + item[-1] + "\n"
                        continue
                    else:
                        newscene += line
    return (newscene)

目标：

lines
BeginObjects
lines
ObjectAlias xxx
lines
BeginKeyframe 34 12    ----> 34 is what I want to replace
lines
EndObject
BeginAnotherObjects
...

Answer 1

你可以使用tell和seek移动文件，所以要做你想做的事情，你可以使用这样的东西，我一起入侵：

import re

# so, we're looking for the object 'HeyThere'
objectname = 'HeyThere'

with open('input.txt', 'r+') as f:
    line = f.readline()
    pos = f.tell()
    found = False
    while line:

        # we only want to alter the part with the 
        # right ObjectAlias, so we use the 'found' flag
        if 'ObjectAlias ' + objectname in line:
            found = True
        if 'EndObject' in line:
            found = False

        if found and 'BeginKeyframe' in line:

            # we found the Keyframe part, so we read all lines 
            # until EndKeyframe and count each line with 'default'
            sub_line = f.readline()
            frames = 0
            while not 'EndKeyframe' in sub_line:
                if 'default' in sub_line:
                    frames += 1
                sub_line = f.readline()

            # since we want to override the 'BeginKeyframe', we
            # have to move back in the file to before this line
            f.seek(pos)

            # now we read the rest of the file, but we skip the
            # old 'BeginKeyframe' line we want to replace
            f.readline()
            rest = f.read()

            # we jump back to the right position again
            f.seek(pos)

            # and we write our new 'BeginKeyframe' line
            f.write(re.sub('\d+', str(frames), line, count=1))

            # and write the rest of the file
            f.write(rest)
            f.truncate()
            # nothing to do here anymore, just quit the loop
            break

        # before reading a new line, we keep track
        # of our current position in the file
        pos = f.tell()
        line = f.readline()

这些评论几乎可以解释发生了什么。

给出像

这样的输入文件

foo
bar
BeginObject
something
something
ObjectAlias NotMe
lines
more lines
BeginKeyframe 22 12   
foo
bar default
foo default
bar default
EndKeyframe
EndObject
foo
bar
BeginObject
something
something
ObjectAlias HeyThere
lines
more lines
BeginKeyframe 43243 12   
foo
bar default
foo default
bar default
foo default
bar default
foo default
bar
EndKeyframe
EndObject

它将替换

行

BeginKeyframe 43243 12

带

BeginKeyframe 6 12

调用函数中的子函数来处理Python中的同一个文件？

1 个答案: