Using pandas and BeautifulSoup you can achieve your expected output easily:

#Code:

import pandas as pd
import itertools
from bs4 import BeautifulSoup as b
with open("file.xml", "r") as f: # opening xml file
    content = f.read()

soup = b(content, "lxml")
pkgeid =  [ values.text for values in soup.findAll("pkgeid")]
pkgname = [ values.text for values in soup.findAll("pkgname")]
time =  [ values.text for values in soup.findAll("time")]
oper =  [ values.text for values in soup.findAll("oper")]
# For python-3.x use `zip_longest` method
# For python-2.x use 'izip_longest method
data = [item for item in itertools.zip_longest(time, oper, pkgeid, pkgname)] 
df  = pd.DataFrame(data=data)
df.to_csv("sample.csv",index=False, header=None)

#output in `sample.csv` file will be as follows:
2015-09-16T04:13:20Z,Create_Product,10,BBCWRL
2015-09-16T04:13:20Z,Create_Product,18,CNNINT
2018-04-01T03:30:28Z,Deactivate_Dhct,,

You can easily use xml (from the Python standard library) to convert to a pandas.DataFrame. Here's what I would do (when reading from a file replace xml_data with the name of your file or file object):

import pandas as pd
import xml.etree.ElementTree as ET
import io

def iter_docs(author):
    author_attr = author.attrib
    for doc in author.iter('document'):
        doc_dict = author_attr.copy()
        doc_dict.update(doc.attrib)
        doc_dict['data'] = doc.text
        yield doc_dict

xml_data = io.StringIO(u'''YOUR XML STRING HERE''')

etree = ET.parse(xml_data) #create an ElementTree object 
doc_df = pd.DataFrame(list(iter_docs(etree.getroot())))

If there are multiple authors in your original document or the root of your XML is not an author, then I would add the following generator:

def iter_author(etree):
    for author in etree.iter('author'):
        for row in iter_docs(author):
            yield row

and change doc_df = pd.DataFrame(list(iter_docs(etree.getroot()))) to doc_df = pd.DataFrame(list(iter_author(etree)))

Have a look at the ElementTree tutorial provided in the xml library documentation.