Swapping list within list in python

Question

I need to swap list (as I am importing nested list from given input file). Next I need to swap every sub-list for every iteration of loop. The sub-list should be on first position.

I wrote the code but instead of swapping it copying the multiple list:

import numpy as np  
fd =open('circle_input.txt','r')
d=np.loadtxt(fd,delimiter=',',dtype={'names':
('co1','col2','col3'),'formats':('float','float','float')})
  temp1=d
  temp2=d
  for i in range(len(d)):
    temp1[0]=temp1[i]
    temp1[i]=temp2[0]
    print(temp1)

circle_input.txt

0,0,5
10,0,5
0,10,5
-10,0,5
0,-10,5

Answer 1

Copying of list1 to list2 can be done using
list2=list1[:]
Not by:-
list2=list1
where list1 and list2 are list not list of lists

Answer 2

swapping the elements from one numpy array to another( the same concept can apply for list also) array can be done. creating the two variable for storing n-d array This is will work.

import numpy as np  
fd1 =open('circle_input.txt','r')
fd2=open('circle_input.txt','r')
d1=np.loadtxt(fd1,delimiter=',',dtype={'names':('co1','col2','col3'),'formats':('float','float','float')})
d2=np.loadtxt(fd2,delimiter=',',dtype={'names':('co1','col2','col3'),'formats':('float','float','float')})
temp1=d1
temp2=d2


for i in range (len(d)):
  if i==0:
   temp1[0]=temp1[i]
   temp1[i]=temp2[0]
  else:
   temp1[0]=temp1[i]
   temp1[i]=temp2[i-1]
  print(temp1)
  print('\n')