I have filea.csv and fileb.csv and I want to make filec.csv. filea has three columns of data:
date,PVkW,TBLkW
2014/12/26 16:00,20.0,307.4633
2014/12/26 17:00,0.0,291.6297
2014/12/26 18:00,0.0,240.87265
2014/12/26 19:00,0.0,251.475
2014/12/26 20:00,0.0,291.81406
2014/12/26 21:00,0.0,268.26328
2014/12/26 22:00,0.0,257.0367
fileb has two columns of data, with matching values for row[0] of filea, but fewer rows:
date,PVkW,TBLkW
2014/12/26 16:00,108.95
2014/12/26 17:00,1.84
2014/12/26 18:00,0.0
For filec, I am trying to replace row[1] in filea with that of fileb when they have the same row[0], and otherwise just write filea's row in filec:
date,PVkW,TBLkW
2014/12/26 16:00,108.95,307.4633
2014/12/26 17:00,1.84,291.6297
2014/12/26 18:00,0.0,240.87265
2014/12/26 19:00,0.0,251.475
2014/12/26 20:00,0.0,291.81406
2014/12/26 21:00,0.0,268.26328
2014/12/26 22:00,0.0,257.0367
Here's what I am working with, adapted from python update a column value of a csv file according to another csv file
import csv
filea = "filea.csv"
fileb = "fileb.csv"
filec = "filec.csv"
delim = ","
a_content = csv.reader(open(filea,"r"), delimiter=delim)
b_content = csv.reader(open(fileb,"r"), delimiter=delim)
datawriter = csv.writer(open(filec, "w"), delimiter=delim)
b_dict = {}
next(b_content)
for row in b_content:
b_dict[row[0]] = row[1]
for row in a_content:
if row[0] in b_dict:
row[1] = b_dict[row[1]]
datawriter.writerow(row)
When I run it (python3), I get the following error:
row[1] = b_dict[row[1]]
KeyError: '0'
How might I produce filec from filea and fileb as described?
