python - 替换 .yml 文件中的一行的程序(PYTHON)

Question

我正在尝试制作一个工具来替换 .yml 文件(作为文本文档打开)中的一行。我让它写入文件，但它取出所有内容并写入“固定”行。我的代码如下，以及一个实例/文件的示例。文件名很重要且无法更改。

import sys
from os import listdir

from os.path import isfile, join
onlyfiles = [ f for f in listdir() if isfile(f) and str(f)[-4:]==".yml" ] #Gets the file names, can be ANYTHING
for pos in range(1, len(onlyfiles)): #So it stops at the end of the List
    with open(onlyfiles[pos], 'r') as a: #Lets open it make sure it is good
        for line in a:
            if line == "  world: Trolling\n": # this is the target line to replace
                line = line.replace("  world: Trolling", "  world: world\n") #rework the line, though it wont write even if i change the R to W
                with open(onlyfiles[pos], 'w') as repl: #Writes to the file, but gets rid of everything else
                    repl.write(line)
                    print(line)

未修改的文档示例:

timestamps:
  login: 1373913158118
  lastteleport: 1373918169442
  logout: 1373918539235
  kits:
    trusted: 1373052268213
ipAddress: 142.165.45.129
nickname: Erin
lastlocation:
  world: Trolling
  x: -890.6999999880791
  y: 87.0
  z: -764.6999999880791
  yaw: 91.99242
  pitch: 75.449974
homes:
  e:
    world: Trolling
    x: 4653.2140183238
    y: 64.0
    z: 80.02726116652944
    yaw: 192.08363
    pitch: 66.29998

我正在尝试将 100 多个文件中的“Trolling”实例替换为“world”，而不触及其他任何内容

Answer 1

当该行与此模式不匹配时，您需要在 if line == "world: Trolling\n" 之后添加一个 else 条件。还将您正在写回的所有数据放入某个变量中，并在关闭您正在读取的文件后一次将其写入最后，您无法同时读取和写入文件。

import sys
from os import listdir 
from os.path import isfile, join

onlyfiles = [ f for f in listdir() if isfile(f) and str(f)[-4:]==".yml" ]

for file in onlyfiles:
  wdata = ''
  with open(file, 'r') as a: #Lets open it make sure it is good
    for line in a: 
        if line == "  world: Trolling\n":
            line = "  world: world\n" # You already know what it should be
        print line
        wdata += line
  with open(file, 'w') as repl: 
    repl.write(wdata)

这样做可能更容易

for file in onlyfiles:
  with open(file, 'r') as f:
    d = f.read().replace('\n  world: Trolling\n','\n  world: world\n')
  with open(file, 'w') as f:
    f.write(d)