extract_green.py

import json

def dump(o, fout):
    json.dump(o, fout, separators=(',', ':'))

data = []

import glob, os
for filename in glob.glob("./data/green-virtual/*.json"):
    with open(os.path.join(os.getcwd(), filename)) as fin:
        jentry = json.load(fin)

        entry = {}
        entry['name'] = jentry['name']
        entry['components'] = 1
        entry['crossing_number'] = jentry['crossing_number']
        entry['alexander'] = jentry['alex']
        arrow = jentry['arrow']
        for i in range(1,4):
            entry[f'arrow{i}'] = arrow[i-1] if i-1 < len(arrow) else None

        data.append(entry)

print("Loaded " + str(len(data)) + " data files")


print("Writing data files")

data.sort(key=lambda o: [int(n) for n in o['name'].split('.')])

# Lazy loader description file
f_defs = open("build/green.js", "w")
f_defs.write("// Generated by extract_green.py from Green database\n")
f_defs.write("// Descriptions of available data files\n")

def write_knots(filename, crossings, components, properties):
    f_defs.write("provides_knot_data(")
    dump(filename, f_defs)
    f_defs.write(", 'green', ")
    dump(components, f_defs)
    f_defs.write(", ")
    dump(crossings, f_defs)
    f_defs.write(", ")
    dump(properties, f_defs)
    f_defs.write(");\n")

    fout = open("build/" + filename, "w")

    fout.write("// generated by extract_green.py from Green database\n")

    fout.write("add_knot_data('green', ")
    dump(properties, fout)
    fout.write(",[\n")

    first = True
    for entry in data:
        if entry['crossing_number'] in crossings and entry['components'] in components:
            if not first:
                fout.write(",\n")
            first = False
            dump(entry['name'], fout)
            for p in properties:
                fout.write(",")
                dump(entry[p], fout)

    fout.write("]);\n")

    fout.write("loaded_knot_data('green', ")
    dump(components, fout)
    fout.write(", ")
    dump(crossings, fout)
    fout.write(", ")
    dump(properties, fout)
    fout.write(");\n")

    fout.close()

properties = ['crossing_number', 'components',
              'alexander',
              'arrow1', 'arrow2']

write_knots("green_0-4.js", [0,1,2,3,4], [1], properties);
write_knots("green_5.js", [5], [1], properties);
write_knots("green_0-4_extra.js", [0,1,2,3,4], [1], ['arrow3']);
write_knots("green_5_extra.js", [5], [1], ['arrow3']);

f_defs.close()

print("Done")