XYZ CSV skipinitialspace

[w-e-w]

Description

if there's a special character in side a CSV value. the value needs to be quoted
the issue is without skipinitialspace "quoting is finicky"

csv.Dialect.skipinitialspace

spaces immediately following the delimiter are ignored

skipinitialspace makes parseing CSV more consistent when quotes are involved

demo
without skipinitialspace (current)

aaa, "b,b",ccc
    ^
# notice that there is a space

will be parsed as 4 item

aaa
"b
b"
ccc

only the input without space is parsed as expected

aaa,"b,b", ccc

to

aaa
b,b
ccc

with skipinitialspace will be parsed as 3 it will consistently parsed as aaa,"b,b", ccc aaa, "b,b",ccc regardless of the extra Spaces

aaa
b,b
ccc

demo test script

rom csv import reader
from itertools import chain
from io import StringIO


def csv_without_skipinitialspace(data_str):
    return list(map(str.strip, chain.from_iterable(reader(StringIO(data_str)))))


def csv_with_skipinitialspace(data_str):
    return list(map(str.strip, chain.from_iterable(reader(StringIO(data_str), skipinitialspace=True))))


def print_list(csv_list):
    for item in csv_list:
        print(item)
        print('-'*10)


if __name__ == '__main__':
    # input_string = '''aaa,"b,b", ccc'''
    input_string = '''aaa, "b,b", ccc'''
    print_list(csv_without_skipinitialspace(input_string))
    print('='*10)
    print_list(csv_with_skipinitialspace(input_string))

Details

output of aaa, "b,b", ccc'

aaa
----------
"b
----------
b"
----------
ccc
----------
==========
aaa
----------
b,b
----------
ccc
----------

aaa,"b,b", ccc'

aaa
----------
b,b
----------
ccc
----------
==========
aaa
----------
b,b
----------
ccc
----------

Checklist:

• I have read contributing wiki page
• I have performed a self-review of my own code
• My code follows the style guidelines
• My code passes tests