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django批量导入xml数据

django后台批量导入数据

在生产环境中,往往数据不是几条或者几百条,那么举个例子,将公司所有员工员工号或者帐号密码导入进后台,那就不建议你去后台一条条记录去添加了

如何从xml中批量导入svn记录

第一步:

为数据建立模型

@python_2_unicode_compatible
class SVNLog(models.Model):

  vision = models.IntegerField(verbose_name=u"修订版本", blank=False, null=False,)
  author = models.CharField(verbose_name=u"作者", max_length=60, blank=True, null=True)
  date = models.DateTimeField(verbose_name=u"修订时间",null=True )
  msg = models.TextField(verbose_name=u"注释消息", blank=False, null=False, default=u"")
  paths = models.TextField(verbose_name=u"影响的文件", blank=False, null=False, default=u"")
  created_time = models.DateTimeField(verbose_name=u"创建时间", auto_now_add=True, )
  update_time = models.DateTimeField(verbose_name=u"修改时间", auto_now=True, )

  class Meta:
    ordering = ['revision']

  def __str__(self):
    return u'r%s' % (self.revision or u"", )

既然建立好了模型,那我们再去建立接受我们xml文件的models

@python_2_unicode_compatible
class ImportLogFile(models.Model):

  LogFile = models.FileField(upload_to='LogFile')
  FileName = models.CharField(max_length=50, verbose_name=u'文件名')

  class Meta:
    ordering = ['FileName']

  def __str__(self):
    return self.FileName

ok,以上代码我们定义好了数据和上传文件的model

同步数据库

python manage.py makemigrations
python manage.py migrate

接着我们去修改admin.py 让我们可以从后台上传文件,

class ImportLogAdmin(admin.ModelAdmin):

  list_display = ('LogFile','FileName',)
  list_filter = ['FileName',]

  def save_model(self, request, obj, form, change):

    re = super(YDImportLogAdmin,self).save_model(request, obj, form, change)
    update_svn_log(self, request, obj, change)
    return re

注意上面代码里的save_model,这里才是关键,在这里我重写了ModelAdmin里的save_model方法
因为我们要把上传文件,读取文件,解析文件,操作数据库合为一步来操作,大家可以打开debug,在上传文件的时候,返回参数的obj里包括了文件上传的路径,这个路径也是下一步我们操作解析文件的关键,好了我们在这个app文件夹下新建一个utils.py 用来操作我们操作文件和数据库的工具类,为了简单我写成了函数如下
先贴一下我们要测试的xml文件

<"1.0" encoding="UTF-8"?>
<log>
<logentry
  revision="2">
<author>qwert</author>
<date>2016-09-27T07:16:37.396449Z</date>
<paths>
<path
  action="A"
  prop-mods="false"
  text-mods="true"
  kind="file">/aaa/README
  </path>
</paths>
<msg>20160927 151630</msg>
</logentry>


<logentry
  revision="1">
<author>VisualSVN Server</author>
<date>2016-09-20T05:03:12.861315Z</date>
<paths>
<path
  action="A"
  prop-mods="false"
  text-mods="false"
  kind="dir">/branches</path>
<path
  action="A"
  prop-mods="false"
  text-mods="false"
  kind="dir">/tags</path>
<path
  action="A"
  prop-mods="false"
  text-mods="false"
  kind="dir">/trunk</path>
</paths>
<msg>hello word</msg>
</logentry>
</log>

输出结果格式

r2 | qwer | 2016-09-27 15:16:37 +0800 (二, 27 9 2016) | 1 line
Changed paths:
  A /xxx/README

20160927 151630
------------------------------------------------------------------------
r1 | VisualSVN Server | 2016-09-20 13:03:12 +0800 (二, 20 9 2016) | 1 line
Changed paths:
  A /branches
  A /tags
  A /trunk

Initial structure.
from .models import SVNLog
import xmltodict
def update_svn_log(self, request, obj, change):

  headers = ['r','a','d','m','p']
  filepath = obj.LogFile.path
  xmlfile = xmltodict.parse(open(filepath, 'r'))
  xml_logentry = xml.get('log').get('logentry')
  info_list = []
  pathlist = []
  sql_insert_list = []
  sql_update_list = []
  for j in xml:
    data_dict = {}
    # get path
    paths = j.get('paths').get('path')
    if isinstance(paths,list):
      for path in paths:
        action = path.get('@action')
        pathtext = path.get('#text')
        pathtext = action + ' ' + pathtext
        pathlist.append(pathtext)
        
      _filelist = u'\n'.join(pathlist)
      _paths = u"Changed paths:\n {}".format(_filelist)
      print _paths
    else:
      _filelist = paths.get('@action') + ' ' + paths.get('#text')
      _paths = u"Changed paths:\n {}".format(_filelist)
      print _paths
    # get revision
    vision = j.get('@vision')
    # get auth
    author = j.get('author')
    #get date
    date = j.get('date')
    #get msg
    msg = j.get('msg')

    data_dict[headers[0]] = int(vision)
    data_dict[headers[1]] = author
    data_dict[headers[2]] = date
    data_dict[headers[3]] = msg
    data_dict[headers[4]] = _paths
    info_list.append(data_dict)

  _svnlog = SVNLog.objects.filter().order_by('-vision').first()
  _last_version = _svnlog.vision if _svnlog else 0

  for value in info_list:
    vision = value['r']
    author = value['a']
    date = value['d']
    msg = value['m']
    paths = value['p']
    print vision,author
    _svnlog = YDSVNLog.objects.filter().order_by('-revision').first()
    _last_version = _svnlog.revision if _svnlog else 0
    if vision > _last_version:
      sql_insert_list.append(SVNLog(revision=revision, author=author, date=date, msg = msg, paths = paths))
    else:
      sql_update_list.append(SVNLog(revision=revision, author=author, date=date, msg = msg, paths = paths))

  SVNLog.objects.bulk_create(sql_insert_list)
  SVNLog.objects.bulk_create(sql_update_list)

我们使用的xmltodict这个第三方库来解析xml,他把内容解析成了高效率的orderdict类型,就是有序列的字典
这个xml中比较复杂的是那个paths里的path,因为这个xml中包含两个元素,第一个元素的path只含有一个path,第二个元素中的paths包含有三个path,因此我们在解析获取的时候需要判断一下

paths = j.get('paths').get('path')
if isinstance(paths,list):
  pass

我们判断这个path是不是一个list类型的,如果是,那我们就按照list的方式来处理,如果不是,那我们就按单个的方式来处理,获取之后按照输出结果格式处理下结果然后获取其他内容

revision = j.get('@vision')
# get auth
author = j.get('author')
#get date
date = j.get('date')
#get msg
msg = j.get('msg')

最后我们将获取到的元素存在字典里
在循环中判断当前的版本号和数据库中的版本号,
如果比原来的小,那么我们执行更新操作,反之执行插入操作

最后使用了bulk_create来操作数据库,这样避免了循环中每次都进行数据库操作造成的资源浪费