[FIXED] How to create array from certain elements in another array?

Issue

I have an array with 7 columns, 52 rows. I want to create an array of just the 4th column but only based a 1 or 0 value from the 7th column. Can someone help?

for row in dataArray:
    if (row[6] == 1):
        sumNSal += int(row[4])
    if (row[6] == 0):
        sumNSalR += int(row[4])
print sumNSal, sumNSalR

My desire is to actually add up some numbers in the 4th column, but only add numbers that correspond to a 0 in the last column. My dataArray is as such: the last column consists of 0's and 1's. Hope this clears up confusion.

['244', '128', '385', '23521', '5230', '5334', '0']
['59', '155', '203', '9160', '2459', '493', '1']
['120', '281', '392', '21900', '6304', '6115', '0']
['120', '291', '419', '22354', '6590', '6346', '0']
['120', '238', '363', '17421', '5362', '6225', '0']
['65', '180', '234', '10531', '3622', '449', '1']
['120', '306', '372', '22147', '4406', '4998', '1']
['90', '214', '305', '14025', '4173', '966', '1']
['96', '155', '169', '8812', '1955', '1260', '0']
['120', '133', '188', '11729', '3224', '6442', '1']
['62', '148', '192', '8896', '2409', '1236', '0']
['120', '274', '426', '20987', '2066', '3360', '1']
['116', '154', '321', '17655', '5946', '4231', '0']
['59', '120', '164', '7085', '1925', '1280', '1']
['80', '261', '284', '13089', '4166', '1123', '1']
['120', '338', '375', '21453', '5257', '5206', '1']
['80', '77', '133', '7790', '1988', '4443', '1']
['100', '204', '318', '18309', '4156', '4585', '1']
['60', '97', '213', '8872', '1914', '1675', '1']
['110', '178', '280', '17881', '5173', '5686', '1']
['120', '232', '336', '17004', '4630', '907', '0']
['135', '316', '442', '23829', '7489', '3351', '0']
['59', '163', '191', '9424', '2051', '1756', '1']
['60', '96', '202', '12474', '3803', '2123', '0']
['25', '74', '83', '4078', '2008', '4531', '1']
['221', '514', '776', '36029', '1288', '2543', '1']
['64', '91', '214', '8782', '4729', '4446', '1']
['62', '146', '204', '8951', '2367', '1064', '0']
['108', '255', '366', '17446', '5933', '2987', '1']
['62', '144', '220', '6164', '2782', '411', '1']
['90', '151', '286', '2853', '4651', '4197', '0']
['146', '100', '375', '21334', '6857', '1198', '0']
['62', '174', '189', '8082', '2143', '1209', '1']
['30', '54', '88', '3948', '3025', '137', '1']
['79', '213', '278', '11649', '2905', '1279', '0']
['44', '127', '158', '7850', '1498', '1273', '1']
['120', '208', '423', '29035', '6236', '3524', '0']
['100', '255', '300', '17532', '3547', '2561', '1']
['49', '110', '177', '8197', '2810', '3874', '1']
['123', '208', '336', '22555', '6059', '6402', '1']
['82', '114', '136', '8459', '1995', '1911', '1']
['58', '166', '205', '10412', '2245', '1122', '1']
['110', '228', '323', '16661', '4029', '3893', '1']
['62', '183', '222', '12406', '2784', '2212', '1']
['86', '62', '200', '11312', '3720', '2959', '1']
['102', '326', '355', '14499', '3866', '3006', '1']
['135', '157', '471', '24274', '7485', '1344', '0']
['78', '154', '203', '9327', '3672', '1242', '1']
['83', '224', '390', '12362', '3995', '1484', '1']
['60', '48', '213', '10644', '2820', '1154', '0']
['54', '119', '144', '7556', '2088', '245', '1']
['120', '217', '327', '20182', '4432', '6274', '0']

Solution

If your 2D list is A, then

# 0-based indexing
# assuming you want to take 4th column only when 7th column is `0`.
# assuming 7th column contains either '1' or '0'
X = [int(row[3]) for row in A if row[6] == '0'] 

X will be a list such that for each row in your 2D list, only those 4th column values will be included if the corresponding value in 7th column is '0'.

This syntax is called List Comprehension and you can read more about it here.

Answered By - Shubham