from xml.dom.minidom import parse
import xml.dom.minidom

dom = xml.dom.minidom.parse(r"path_to_xml file")
file = dom.documentElement
seg = dom.getElementsByTagName("seg")
for item in seg:
    sent = item.firstChild.data
    print(sent,sep='')

file = open(r'file.txt','w')
file.write(sent)
file.close()