BOM parsing and writing

parse.py

import csv

connectors = {}
REF = 0
FOOTPRINT = 1
LABEL = 2

lines = []
with open('my-bom.bom', newline='') as f:
	reader = csv.reader(f, delimiter=';')
	for row in reader:
		if row[REF].startswith('P'):
			if ! connectors[row[FOOTPRINT]]:
				connectors[row[FOOTPRINT]] = []
			
			connectors[row[FOOTPRINT]].append(
				{
					ref: row[REF],
					label: row[LABEL]
				}
			)
		else:
			lines.append(row)

# connectors:

# 02x02: [
# 	{ref: P1, label: LED},
# 	{ref: P2, label: Power In}
# ]

for footprint in connectors:
	lines.append([
		', '.join(map((lambda x: x.ref), connectors[footprint])),
		footprint,
		', '.join(map((lambda x: x.label), connectors[footprint])),
		len(connectors[footprint])
	])

with open('my-new-bom.bom', newline='') as f:
	writer = csv.writer(csvfile, delimiter=';')
	for r in lines:
		writer.writerow(r)