why do I get error when I want to loop

Question

How would I loop the following code, when I use if statements I keep getting an error. I am trying to get the following number printed out, 511887 and Compare each 4-bit binary number using conditional statements but I keep getting an error: NameError: name 'bin_list' is not defined

x=("bin_list")

y=("bin_list[SN_0]")
["0001"]

"0101"
"0001"
"0001"
"1000"
"1000"
"0111"

SN_bin_0 = bin_list[SN_1]
for x in range (0,7):
     for index in range(len(L)):
        print (y)

SN_bin_1 = bin_list[SN_5]
   for x in range (1,7):
     for index in range(len(L)):
        print (y)

SN_bin_2 = bin_list[SN_1]
   for x in range (2,7):
     for index in range(len(L)):
        print (y)


SN_bin_3 = bin_list[SN_1]
   for x in range (3,7):
     for index in range(len(L)):
        print (y)

SN_bin_4 = bin_list[SN_8]
   for x in range (4,7):
     for index in range(len(L)):
        print (y)

SN_bin_5 = bin_list[SN_8]
   for x in range (5,7):
     for index in range(len(L)):
        print (y)

SN_bin_6 = bin_list[SN_7]
   for x in range (6,7):
     for index in range(len(L)):
        print (y)

Answer 1

1. Making a List

Instead of writing:

["0001"]
"0101"
"0001"
"0001"
"1000"
"1000"
"0111"

You can make it a list:

bin_list = ["0101","0001","0001","1000","1000","0111"]

Explanation:

• This is the proper way of making a list: variable = [item1,item2,item3]
• It should be a list because later you will use an index to refer to the items inside of it. For example bin_List[1] will return the string "0001".

2. Value of Variable x

Instead of writing:

x=("bin_list")

You should do:

x=(bin_list)

Explanation:

• The quotation marks on bin_list makes it a string. You want the value of x to be the list bin_list.
• You must make create the (see step 1) before assigning the variable x to it.

3. Value of Variable y

Instead of writing:

y=("bin_list[SN_0]")

You should do:

y= bin_list[SN_0]

Explanation:

• The quotation marks on bin_list[SN_0] makes it a string. You want the value of y to be the item at index [SN_0] of the list bin_list.

4. Undefined variable

The following are undefined:

[SN_0]
[SN_1]
[SN_5]
[SN_8]
L

Each one of them needs a value, for example:

SN_0 = 0
SN_1 = 1
SN_5 = 5
SN_8 = 8
L = x

Explanation:

• Undefined variables will return an error.
• They must all be defined before being used in the for loops.
• If L is supposed to refer to the list, you can replace it with x since the list is already assigned variable x.

4. Indentation

The following code has an extra indentation:

SN_bin_1 = bin_list[SN_5]
   for x in range (1,7):
     for index in range(len(L)):
        print (y)

SN_bin_2 = bin_list[SN_1]
   for x in range (2,7):
     for index in range(len(L)):
        print (y)


SN_bin_3 = bin_list[SN_1]
   for x in range (3,7):
     for index in range(len(L)):
        print (y)

SN_bin_4 = bin_list[SN_8]
   for x in range (4,7):
     for index in range(len(L)):
        print (y)

It should be:

SN_bin_1 = bin_list[SN_5]
for x in range (1,7):
     for index in range(len(L)):
        print (y)

SN_bin_2 = bin_list[SN_1]
for x in range (2,7):
     for index in range(len(L)):
        print (y)


SN_bin_3 = bin_list[SN_1]
for x in range (3,7):
     for index in range(len(L)):
        print (y)

SN_bin_4 = bin_list[SN_8]
for x in range (4,7):
    for index in range(len(L)):
        print (y)

Answer 2

It looks like there are few issues with your code. The following is not valid python:

x=("bin_list")

y=("bin_list[SN_0]")
["0001"]

"0101"
"0001"
"0001"
"1000"
"1000"
"0111"

I think what you wanted was to have these values in a list, which can be done like so:

bin_list = ["0101", "0001", "0001", "1000", "1000", "0111"]

Next, you are accessing the list using an undefined variable. You need to either use an integer or define SN_0 beforehand.

y = bin_list[0]

or

SN_0 = 0
y = bin_list[SN_0]

Finally, your indentation is off on most of the loops. You have:

SN_bin_1 = bin_list[SN_5]
   for x in range (1,7):
     for index in range(len(L)):
        print (y)

You want:

SN_bin_1 = bin_list[SN_5]
for x in range (1,7):        # <-- one less indent here
  for index in range(len(L)):
     print (y)

I can't exactly tell what your code is meant to do, it seems you are not using many of your variables, and your goal to print the value of y a certain amount of times. Once you've fixed these errors, open a new question if the code is still not doing what you intended.