Its bit confusing that I haven't gone any assignment of list a[] with list coy, still on output I get ,list a, same as ,list coy.I mean , how is that happening when I used coy=a[:].Thanks .
T=int(input())
for i in range(T):
a=[]
z=[]
f=0
count=0
n,m=map(int,input().split())
for i in range(n):
a+=[list(map(int,input().split()))]
coy=a[:]
print(coy,'coy')#debug
print(a,'a')#debug
while(f==0):
for i in range(n):
for j in range(m):
if i==0 and j==0:
coy[0][0]=max(a[i][j+1],a[i+1][j+1],a[i+1][j])
elif i==0 and j==m-1:
coy[i][j]=max(a[i][j-1],a[i+1][j],a[i+1][j-1])
elif i==n-1 and j==0:
coy[i][j]=max(a[i][j+1],a[i-1][j],a[i-1][j+1])
elif i==n-1 and j==m-1:
coy[i][j]=max(a[i-1][j],a[i][j-1],a[i-1][j-1])
elif j==0:
coy[i][j]=max(a[i][j+1],a[i-1][j],a[i+1][j],a[i-1][j+1],a[i+1][j+1],)
elif j==m-1:
coy[i][j]=max(a[i][j-1],a[i-1][j],a[i-1][j-1],a[i+1][j],a[i+1][j-1])
elif i==0:
coy[i][j]=max(a[i][j-1],a[i+1][j],a[i+1][j-1],a[i][j+1],a[i+1][j+1])
elif i==n-1:
coy[i][j]=max(a[i][j-1],a[i-1][j-1],a[i-1][j],a[i-1][j+1],a[i][j+1])
else:
coy[i][j]=max(a[i][j-1],a[i-1][j],a[i-1][j-1],a[i+1][j],a[i+1][j-1],a[i][j+1],a[i-1][j+1],a[i+1][j+1])
print('inside else','coy',coy,'a',a)#debug
if(coy==a):
print(coy,'coy')#debug
print(a,'a')#debug
count=0
break
for x in range(n):
print('*')#debug
z+=set(copy[x])
print(z)
if len(set(z))==1:
f=1
a=copy[:]
count+=1
print('**********')#debug
print(count)
I have used some print statement for viewing the flow, and the value of ,list a, gets changed during assignment of list coy indices, which ideally shouldn't.
