Python變量作用域的兩個功能

Question

我試圖搜索該問題，但找不到實際答案。 我正在嘗試實現一個函數（magic_debug），以便在另一個函數（somefunc）中調用時，它可以訪問somefunc中的變量，並按如下所示打印出來：

def magic_debug(s, *args, **kwargs):
    s2 = s.format(x=x,y=y,z=args[0])
    print(s2)


def somefunc():
    x = 123
    y = ['a', 'b']
    magic_debug('The value of x is {x}, and the list is {y} of len {z}', len(y))

somefunc()

預期的輸出-> x的值為123，列表為len 2的['a'，'b']

Answer 1

這確實是一個常見問題，請嘗試使用inspect 。

def magic_debug(s, *args, **kwargs):
    import inspect
    parent_local_scope = inspect.currentframe().f_back.f_locals
    s2 = s.format(**parent_local_scope, z=args[0])
    print(s2)


def somefunc():
    x = 123
    y = ['a', 'b']
    magic_debug('The value of x is {x}, and the list is {y} of len {z}', len(y))

somefunc()

輸出：

The value of x is 123, and the list is ['a', 'b'] of len 2

Answer 2

你是真的嗎

def magic_debug(s, vars_dict):

    s2 = s.format(**vars_dict)
    print(s2)


def somefunc():
   x = 123         # variables are indent in python
   y = ['a', 'b']  # so they're in the function scope

                   # and so is this function that somefunc calls - 
   vars_dict = vars()
   vars_dict['z'] = len(y)
   magic_debug('The value of x is {x}, and the list is {y} of len {z}', vars_dict)

somefunc()

Answer 3

試試看-您需要縮進功能

def magic_debug(s, *args, **kwargs):

    s2 = s.format(x=x,y=y,z=args[0])
    print(s2)


def somefunc():
   x = 123         # variables are indent in python
   y = ['a', 'b']  # so they're in the function scope

                   # and so is this function that somefunc calls - 
   magic_debug('The value of x is {x}, and the list is {y} of len {z}', len(y))

somefunc()

Answer 4

更改一些代碼，使其看起來像這樣：

def magic_debug(s, *args, **kwargs):
    s2 = s.format(x=args[1],y=kwargs.pop('y', ''),z=args[0])
    print(s2)


def somefunc():
    x = 123
    y = ['a', 'b']
    magic_debug('The value of x is {x}, and the list is {y} of len {z}', len(y), x, y=y)

somefunc()

您的輸出將是完美的。 您要添加** Kargs，但不使用它。 上面的代碼使用** Karg存儲數組。

輸出：

The value of x is 123, and the list is ['a', 'b'] of len 2

編輯較少的參數：

def magic_debug(s, *args, **kwargs):
    s2 = s.format(x=args[1],y=args[0],z=len(args[0]))
    print(s2)


def somefunc():
    x = 123
    y = ['a', 'b']
    magic_debug('The value of x is {x}, and the list is {y} of len {z}', y, x)

somefunc()

Answer 5

如果您只要保留問題的實質就可以進行任何修改，則可以使用locals()將本地范圍傳遞給magic_debug函數，即：

def magic_debug(s, *args, **kwargs):
    s2 = s.format(z=args[0], **kwargs)
    print(s2)

def somefunc():
    x = 123
    y = ['a', 'b']
    magic_debug('The value of x is {x}, and the list is {y} of len {z}', len(y), **locals())

somefunc()
# The value of x is 123, and the list is ['a', 'b'] of len 2

而且，如果允許您更改函數簽名，則也可以不擴展而傳遞locals() 。 但是，如果您無法更改要調試的功能，則只能查看前一幀。 @Sraw已經在他的回答中提到了 。