Stuff

import xml.etree.ElementTree as etree
import copy

def main(i):
    tree = etree.parse('test_project_write.xml')
    root = tree.getroot()
    Project = root.find('Projects/Project')
    Project.attrib['projectID'] = 'Нагрузочное' + str(i)
    Blines = Project.find('ProjectBaselines')
    baseline = Blines.find('ProjectBaseline')
    for j in range(2, 51):
        #creating new
        new_baseline = copy.deepcopy(baseline)
        new_baseline.attrib['revisionID'] = str(j)
        new_baseline.attrib['name'] = str(j)
        Blines.append(new_baseline)
                          
    tree.write('out2.xml', 'UTF-8')


if __name__ == "__main__": main(2)