input: Write a function that prints out Pascal's triangle for a given number of rows. The function should return True if the number of rows is greater than or equal to 1, otherwise it should return False.
  assert pascal_triangle(5)==True
  assert pascal_triangle(0)==False
  assert pascal_triangle(3)==True
  assert pascal_triangle(1)==True
  assert pascal_triangle(10)==True
output: def pascal_triangle(n):
      if n < 1:
          return False
      triangle = [[1]]
      for i in range(1, n):
          row = [1]
          for j in range(1, i):
              row.append(triangle[i-1][j-1] + triangle[i-1][j])
          row.append(1)
          triangle.append(row)
      for row in triangle:
          print(' '.join(map(str, row)).center(n*3))
      return True