"IndentationError: Expected an indented block" but when I fix it, I get "Syntaxerror: Invalid syntax"

Question

我似乎无法弄清楚为什么会收到这些错误消息。我试过多次重新输入我的代码，但还是行不通。

def check_if_win():

  row_winner = check_rows()
  diagnal_winner = check_diagnals()
  column_winner = check_columns()
  if row_winner:
    #Row Win
  elif column_winner:
    #Column_Winner
  elif diagnal_winner:
    #Diagnal Win
  else:
    winner = None
  return

Answer 1

def check_if_win():

    row_winner = check_rows()
    diagnal_winner = check_diagnals()
    column_winner = check_columns()
    if row_winner:
      #Row Win
        None
    elif column_winner:
      #Column_Winner
        None
    elif diagnal_winner:
      #Diagnal Win
        None
    else:
        winner = None
    return None

会工作

"IndentationError: Expected an indented block" but when I fix it, I get "Syntaxerror: Invalid syntax"

"IndentationError: Expected an indented block" but when I fix it, I get "Syntaxerror: Invalid syntax"

python

syntax-error