set - Python - Iterating through two files to create a new file that has fields from second file appended to fields of first file -

new python attempted use logic answers in @mgilson, @endolith, , @zackbloom zack's example

1. i getting bunch of blank columns placed in front of first field of primary record.
2. my out_file empty (more because of columns 2 files cannot match up.

how can fix this? end result should following:

('pudo_id','load_id','carrier_id','pudo_from_company','pudoitem_id';'pudo_id';'pudoitem_make')               ('1','1','14','fmh material handling solutions','1','1','crown','tr3520 / twr3520','tuggers') ('2','2','7','wiese usa','2','2','cat','ndc100','3','2','cat','ndc100','4','2',' 2 batteries') 

note: in output of 3rd row, appended 3 rows sub file array, while first 2 rows appended 1 row sub file. determined value in pri[0] , sub[1] comparing true.

here code based on @zack bloom:

def build_set(filename):     # set stores collection of unique items.  both adding items , searching them     # quick, it's perfect application.     found = set()      open(filename) f:         line in f:                 # tuples, unlike lists, cannot changed, requirement                 # being stored in set.                 line = line.replace('"','')                 line = line.replace("'","")                 line = line.replace('\n','')                 found.add(tuple(sorted(line.split(';'))))     return found  set_primary_records = build_set('c:\\temp\\oz\\loads_pudo.csv') set_sub_records     = build_set('c:\\temp\\oz\\pudo_items.csv') record                  = []  open('c:\\temp\\oz\\loads_pudo_out.csv', 'w') out_file:    # using open files ensures closed, if code    # raises exception.      pri in set_primary_records :         sub in set_sub_records :             #out_file.write(" ".join(res) + "\n")             if sub[1] == pri [0] :                 record = pri.extend(sub)             out_file.write(record + '\n') 

sample source data (primary records):

pudo_id;"load_id";"carrier_id";"pudo_from_company"               1;"1";"14";"fmh material handling solutions"                 2;"2";"7";"wiese usa" 

sample source data (sub records):

pudoitem_id;"pudo_id";"pudoitem_make" 1;"1";"crown";"tr3520 / twr3520";"tuggers" 2;"2";" cat";"ndc100" 3;"2";"cat";"ndc100" 4;"2";" 2 batteries" 5;"11";"midland" 

the extend attribute not available tuples build_set creating. tuples immutable can concatenated or sliced normal python string functions.

for example:

with open('c:\\temp\\oz\\loads_pudo_out.csv', 'w') out_file:     pri in set_primary_records :         sub in set_sub_records :             if sub[1] == pri[0] :                 record = pri + sub                 out_file.write(str(record)[1:-1] + '\n') 

this same code above, modified allow tuple concatenation. in write line convert record string , strip start , end brackets, before appending '\n'. maybe there better / prettier ways this, i'm new python too.

edit: output expecting, few changes required:

# on line, remove sort() not wish change tuple item order.. found.add(tuple(line.split(';')))  ...  open('c:\\temp\\loads_out.csv', 'w') out_file:     pri in set_primary_records:         record = pri                        # record tuple set in main loop         sub in set_sub_records:             if sub[1] == pri[0]:                 record += sub               # each match, sub appended record         out_file.write(str(record) + '\n')  # removed stripping of brackets