while for loop combination can't end up while loop

I will answer to the first question, maybe you could provide a bit more detail on what it should do once it passes the else then. I have the feeling you want the code to do something completely different than what it does right now.

I hope it helps, although it is quite some text.

Let's look at the execution:

• you define your variables loc_number = 10, k = 2.
• the code checks, if k < 3 which is true.
• you define a range from 0 to int(len(target_df.index)/loc_number) = 450 in steps of loc_number = 10, which is an iterator which will set i = 0 in the first iteration
• Now that i = 0, the code prints 10 0 and you calculate the sum of all elements of the dataframe from row 0 to row i + loc_number = 0 + 10 = 10. This returns a value for each column, which is again printed.
• Now, you check if any of those values is smaller than 3 (x < 3), and if so, you increase loc_number by 1 (loc_number = 11), print 'heloo' and break out of the for loop.
• The code prints 'probably'
• As k < 3 == True, you initialize a new for loop with range(0, 409, 11) (ranging from 0 to 14 in steps of 11), which will again set i = 0 in the first iteration.
• Now that i = 0, the code prints 11 0 and you calculate the sum of all elements of the dataframe from row 0 to row i + loc_number = 0 + 11 = 11. This returns a value for each column, which is again checked if any of these is smaller than 3.
• As this is the case, loc_number += 1 = 12, it prints 'heloo' and you break out of the for loop again. The code prints 'probably'
• This is repeated until loc_number = 322. Now, the range(0, 14, 322) only returns 0, so the for loop only sets i = 0, and you sum from row 0 to row 322, the code prints 322 0
• Now, no value is smaller than 3, so the any(x < 3) evaluates to False and the else is invoced. There, loc_number stays the same and the code prints 'here'.
• As the for loop does not find another element in the range() iterator, the for loop is ended and the code prints 'probably'.
• You now initialize a for loop with unchanged range(0, 14, 322), which executes the same as before, no value is smaller than 3.
• This circle never breaks, as the while statement is always true.

Perhaps one point of confusion is, that the for in python behaves like foreach in other languages.

Also, I'd suggest to run the following code snippet to better understand the range(start, stop, step) function, as I think this also behaves differently than you assumed:

for i in range(0, 5, 2):
    print(i)

for k in range(0, 5, 10):
    print(k)