导入模块时不了解此KeyError的原因

Question

我刚开始使用Python创建模块，我想创建一个模块并导出结果。到目前为止，我拥有以下内容，并且将模块命名为Card_module：

from random import shuffle

def Cards(deck,colour):
    for item in colour:
        return (item,deck)

def Vdeckk():
    colour=['RED', 'YELLOW', 'BLACK']
    deck=[]
    deck=[Cards(value,colour)for value in range(1,11)]
    return (deck)

if __name__=='__main__':
    Vdeckk()

当我运行import Card_module然后Card_module.Vdeckk()时，我收到以下错误消息：

Traceback (most recent call last):
  File "<ipython-input-61-8a304a818b2c>", line 1, in <module>
    Card_module.Vdeckk()
  File "C:\Users\mnazari\AppData\Local\Continuum\anaconda3\lib\site-packages\IPython\core\displayhook.py", line 258, in __call__
    self.update_user_ns(result)
  File "C:\Users\mnazari\AppData\Local\Continuum\anaconda3\lib\site-packages\IPython\core\displayhook.py", line 196, in update_user_ns
    if result is not self.shell.user_ns['_oh']:
KeyError: '_oh'