Python 2.7 如何将数据替换为文件的一行？

我有一个文件如下

sys.test1.username = user1
sys.test1.pwd = 1234
sys.test2.username = user2
sys.test2.pwd = 1234

我想将sys.test1.pwd的pwd更改为sys.test1.pwd=4321

读取文件

with open (tempfile, 'r') as tempFile:
            return self.parse_cfg (self, tempFile.readlines ())

这是搜索sys.test1.pwd并获取值

def parse_cfg (self, lines):
        """ Parse ubnt style configuration into a dict"""
        ret_dict = {}
        for line in lines:
            line = line.strip () # remove new lines
            if not line: continue # skip empty lines


            key, value = line.split ('=') # key = value
            print "key %s" %key 

            if key == 'sys.test1.pwd':
                key = key.strip ()            
                value = value.strip ()

                # logic to parse mainkey.subkey.subkey structure into a dict
                keys = key.split ('.') 
                tempo = ret_dict
                for each in keys[:-1]:
                    tempo.setdefault (each, {})
                    tempo = tempo[each]
                tempo[keys[-1]] = value

                break

        return ret_dict

---

但我不知道如何将sys.test1.pwd=4321写入文件。请帮助我

我不确定你的确切问题是什么，所以我会尽力回答你的问题

要将其写入同一个文件还是另一个文件

基本上，要写入文件，您需要打开具有写入权限的文件-

termFileWrite = open (tempfile, 'w')

termFileWrite.write(yourText)

如果您要求以上述格式写入文件，则应为：

myString = ""
for k,v in dict.iteritems():
    myString+=k+"="+v+"\n"
termFileWrite.write(myString)

这应该行得通

import re

def searchReplace(file, search, replace):
    with open (file,'r') as f:
        f_content= f.read()
    # Re to search and replace
    f_content = (re.sub(search, replace, f_content))
    #write file with replaced content
    with open (file,'w') as f:
        f.write(f_content)


searchReplace("file.txt","sys.test1.pwd = 1234","sys.test1.pwd = 4321")

---

很好的解决方案。您可能希望为正则表达式传递原始字符串，以防万一。。。否则，如果你想按字面意思去做，我想你可以使用

.replace