Answer 1

def pat(n):

if n>0 and n<=1000:

for i in range(n):
p=1
for j in range(n):
print(p,end='')
if p < n:
print('_',end='')
p=p+1
print()

n=int(input())
pat(n)

Answer 2

Basically you have to add a condition that checks if it's the last line, and if it is then change the print statement.

def pat(n):
if n>0 and n<=1000:
for i in range(n):
p=1
for j in range(n):
if j != n-1:
print(p,end='_')
else:
print(p,end='')
p=p+1
print()

n=int(input())
pat(n)