Question

I have a file I am putting into a list and I am wanting to take some things out of it, and append to another list ( I have no problem with that), the problem I run into is removing the things out of the first list. below is what I have tried but it only removes every other from the original list.

list:
bob     g1  3110
bob     g2  244
bob     g3  -433
greg    fun112  10595
greg    fun113  -1203
greg    fun114  -3049.999
greg    fun115  3808
greg    fun116  320
greg    got112  -600
greg    got113  5958
greg    got114  1249


file1 = open('test','rb').read().splitlines()
file1=sorted(file1)
test_group = ['fun','got']
test= []

for product in file1:
    spt = product.split(",")
    for line in spt:
        if line[:3] in test_group:
            x = test.append(product)
            y = file1.remove(product)

the test [ ] list is fine all of the items I want in there go with no problem, but when I review file1 it only takes out every other one of ‘fun’ and ‘got’ lines

why is this only taking out every other one, and how do I fix it?

Answer 1

Don’t try to modify a list you’re iterating over! That’s not going to work!

If you make a copy of the list, then it should work:

for product in file1[:]:
    spt = product.split(",")
    for line in spt:
        if line[:3] in test_group:
            x = test.append(product)
            y = file1.remove(product)