input: Write a function to generate and print a Pascal triangle with a given number of rows. If the given number of rows is 0, print nothing.
  def PascalTriangle(n):
      arr = [0 for i in range(n)]
      for line in range(0, n):
          for i in range (0, line + 1):
              if (i == 0 or i == line):
                  arr[i] = 1
              else:
                  arr[i] = arr[i] + arr[i - 1]
          for i in range (0, line + 1):
              print(arr[i], end =" ")
          print()
  
  assert PascalTriangle(5)==None
  assert PascalTriangle(0)==None
  assert PascalTriangle(1)==None
  assert PascalTriangle(3)==None
  assert PascalTriangle(7)==None
output: def PascalTriangle(n):
      for line in range(n):
          arr = [1] * (line + 1)
          for i in range(1, line):
              arr[i] = arr[i-1] + arr[i]
          print(' '.join(map(str, arr)))