cobudget_merge.py

#!/usr/bin/env python
import sys
import csv

'''
usage: ./cobudget_merge.py file1.csv file2.csv ... fileN.csv

combine cobudget allocations across mulitple files and print result to stdout.
take the full outer join of the rows in each file, *summing* balances if an
email is present multiple times. 

Assumes each file has NO headers, and the first two columns are as follows: 
email, amount. 

Other columns may be present and will be ignored. If a row has a $0 amount
value, it will be skipped. 

'''

allocations = {}

# start with the second argument (index 1), and iterate until there's no more
# files. 
num_files = len(sys.argv)
total_allocated = 0
for n in range(1,num_files):
    the_file = sys.argv[n]
    sys.stderr.write("\n\n**** %s ****\n\n" % the_file)
    open_file = open(the_file, 'r')
    the_csv = csv.reader(open_file, delimiter=",")
    allocated_this_file = 0
    for row in the_csv:
        try:
            # row is a list of strings
            # row[0] is email
            # row[1] is amount
            # other rows MAY be present, this specifically allows for that and will ignore them. 
            # strip any surrounding whitespace
            email = row[0].strip()
            new_allocation = float(row[1])
            if new_allocation == 0:
                continue
        except:
            # if there's a comment row or some other non conforming row in the
            # file, skip it. 
            continue
        balance = allocations.get(email, 0.0)
        if balance > 0:
            sys.stderr.write('%s: found existing balance of %s. appending new allocation of $%f.\n' % (email, balance, new_allocation))
        else:
            sys.stderr.write("adding new user %s with allocation of $%s\n" % (email, new_allocation))
        allocations[email] = balance + new_allocation
        allocated_this_file += new_allocation
    sys.stderr.write("\nAllocated this file: %f\n" % allocated_this_file)
    total_allocated += allocated_this_file

sys.stderr.write("\nTotal allocated: %f\n" % total_allocated)

sys.stderr.write("\n\n")

emails = allocations.keys()
all_emails = ",".join(emails)

sys.stderr.write("\nAll Group Emails (should you want to bulk email your group):\n\n")
sys.stderr.write("%s\n" % all_emails)

sys.stderr.write("\n\n")

for email, amount in allocations.iteritems():
    print "%s,%f" % (email, amount)