python - Join lists by value -

is there efficient way merge 2 lists of tuples in python, based on common value. currently, i'm doing following:

name = [          (9, "john", "smith"),          (11, "bob", "dobbs"),          (14, "joe", "bloggs")          ]  occupation = [               (9, "builder"),               (11, "baker"),               (14, "candlestick maker")               ]  name_and_job = []  n in name:     o in occupation:         if n[0] == o[0]:             name_and_job.append( (n[0], n[1], n[2], o[1]) )   print(name_and_job) 

returns:

[(9, 'john', 'smith', 'builder'), (11, 'bob', 'dobbs', 'baker'), (14, 'joe', 'bloggs', 'candlestick maker')] 

while code works fine small lists, it's incredibly slow longer lists millions of records. there more efficient way write this?

edit numbers in first column unique.

edit modified @john kugelman's code slightly. added get(), in case names dictionary doesn't have matching key in occupation dictionary:

>>>> names_and_jobs = {id: names[id] + (jobs.get(id),) id in names} >>>> print(names_and_jobs) {9: ('john', 'smith', none), 11: ('bob', 'dobbs', 'baker'), 14: ('joe', 'bloggs', 'candlestick maker')} 

use dictionaries instead of flat lists.

names = {     9:  ("john", "smith"),     11: ("bob", "dobbs"),     14: ("joe", "bloggs") }   jobs = {     9:  "builder",     11: "baker",     14: "candlestick maker" } 

if need convert them format, can do:

>>> {id: (first, last) id, first, last in name} {9: ('john', 'smith'), 11: ('bob', 'dobbs'), 14: ('joe', 'bloggs')} >>> {id: job id, job in occupation} {9: 'builder', 11: 'baker', 14: 'candlestick maker'} 

it'd piece of cake merge two.

names_and_jobs = {id: names[id] + (jobs[id],) id in names}