osm_cygnus_multiple_files_merger.py

import glob
import os
import xml.etree.cElementTree as ET
#TODO Interator over a specifc folder,
#TODO increase value by 100000 for each new file

input_folder = './../../cygnus_output/output/'
output_folder = './../../step_11_ready2merge_output/'

start_number = 1
increase_number_by = -100000

from xml.etree.ElementTree import Element, SubElement

def renumber_func(current_file,start_number,increase_number_by):

    tree = ET.ElementTree(file=input_folder + current_file)
    root = tree.getroot()


    for elem in root:
        attrs = elem.attrib
        id = int(attrs['id'])


        if id < 0: # We want to modify just the negative id`s.
            elem.set('id',str(int(id) + int(increase_number_by * start_number))) # The result needs to be passed to the XML as a string

        if elem.tag =='way': # This is implemented only for ways. If will FAIL if you have relations.
            for sub_elem in elem:
                if sub_elem.tag == 'nd': # We ignore other tags such as tag
                    sub_attrs = sub_elem.attrib
                    ref = int(sub_attrs['ref'])

                    if ref < 0: # We want to modify just the negative id`s.
                        sub_elem.set('ref', str(int(ref) + int(increase_number_by * start_number)))
                        print (sub_elem.attrib)

    tree.write(output_folder + "ready2merge_" + current_file, "UTF-8")

for osm in glob.glob1(input_folder,'osmosis*.osm'): #The script is located in ./scripts/python_script_renumber_cygnus.
    # And the output files are located in ./cygnus_output/output/
    renumber_func(osm,start_number,increase_number_by)
    start_number = start_number + 1
    print (osm)