Python 用file 对象和open方法处理文件的区别

最近用python处理文件时碰到一个错误，让我仔细对这种用法有了一些深入的研究：

python document 是这么说的：

File objects are implemented using C’s stdio package and can be created with the built-inopen() function. File objects are also returned by some other built-in functions and methods, such asos.popen() andos.fdopen() and themakefile() method of socket objects. Temporary files can be created using thetempfile module, and high-level file operations such as copying, moving, and deleting files and directories can be achieved with theshutil module.

并且对File 对象的构造函数说明如下：

file(filename[,mode[, bufsize]])

Constructor function for the file type, described further in sectionFile Objects. The constructor’s arguments are the same as those of theopen() built-in function described below.

When opening a file, it’s preferable to use open() instead of invoking this constructor directly.file is more suited to type testing (for example, writingisinstance(f, file)).

New in version 2.2.

但是其实我在如下代码段中，

def setNodeManagerDomain(domainDir):
   try:   
    domainName = os.path.basename(domainDir)
    fd = open(domainDir + '/nodemanager/nodemanager.domains', 'w')
    fd.write('#Domains and directories created by Configuration Wizard.\n')
    fd.write('#' + time.ctime() + '\n')
    dirNorm=os.path.normpath(domainDir).replace('\\','\\\\')
    fd.write(domainName + '=' + dirNorm)
    print 'create domain file and close in the end under the directory:' + domainDir
    fd.close
   except Exception, e:
    print 'Failed to create domain file in the directory:' + domainDir

我使用file对象 or open方法在windows 环境下都能通过，但是程序部署到Linux环境中就出现问题。

    [echo] NameError: file

可能linux环境对file支持不好，所以保险起见，还是遵循文档中所说的，坚持用open方法吧。