not processing the first row in CSV

Question

In the following code how can I escape processing the first rows for print int(value) - int(dict2[key]) ?

file1 = open("file1.csv", "r")
file2 = open("file2.csv", "r")

csv_reader1 = csv.reader(file1)
csv_reader2 = csv.reader(file2)

dict1 = {}
for row in csv_reader1:
    dict1[row[0],row[1]] = row[2]
dict2 = {}
for row in csv_reader2:
    dict2[row[0],row[1]] = row[3]

for key, value in dict1.iteritems():
    print key, value

for key, value in dict2.iteritems():
    print key, value

for key, value in dict1.iteritems():
    if key in dict2.keys():
        print int(value) - int(dict2[key])

file1.csv is :

name, last_name, age, city, birthday, date
mona, jalal, 28, Madison, 7/23/1987, 5/31/2016
james, cardel, 29, DC, 7/23/1986, 5/1/2016
kate, spade, 30, NYC, 7/32/1985, 5/24/2016

and file2.csv is:

name, last_name, pet, pet_age
mona, jalal, cat, 2
kate, spade, dog, 3
mina, nik anjam, bird, 1

I am trying to subtract the age of person and his/her pet if it appears in both CSVs but I get the following error because it processes the first row as well:

Traceback (most recent call last):
26
  File "/Users/mona/PycharmProjects/PythonCodes/CSV_calculation.py", line 27, in <module>
27
    print( int(value) - int(dict2[key]) )
ValueError: invalid literal for int() with base 10: 'age'

Process finished with exit code 1

use csv.DictReader it will be really easy to map using name afterwards — DevLounge, May 31 '16 at 20:32
I want to create the dictionary myself not to use .DictReader @Apero — Mona Jalal, May 31 '16 at 20:34

score 2 · Answer 1 · answered May 31 '16 at 20:29

2

Skip the first rows:

csv_reader1 = csv.reader(file1)
next(csv_reader1) # skip 1st row
csv_reader2 = csv.reader(file2)
next(csv_reader2) # skip 1st row

answered May 31 '16 at 20:29

Daniel

40,885
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score 2 · Accepted Answer · edited May 23 '17 at 12:15

2

To skip the first line use next() then continue your code:

next(csv_reader1, None)

This is a dupe of this question

edited May 23 '17 at 12:15

Community

1
1

answered May 31 '16 at 20:31

EoinS

5,106
1
17
31

2

The `None` argument protects you from `StopIteration` being raised when the file is empty. – Steven Rumbalski May 31 '16 at 20:33
Thanks for the details about `None` – Mona Jalal May 31 '16 at 20:35

not processing the first row in CSV

2 Answers2