的Python：從字典

Question

創建功能如何創建計算從2給出字典

Answer 1

如果你有一個像這樣的數據總量值的函數：

Part = collections.namedtuple('Part', 'key name price') 
parts = { 
    'WH239': Part('WH239', 'Mountain Bike Wheel', 5000), 
    'TR202': Part('TR202', 'Mountain Bike Tire', 2000), 
    'TU277': Part('TU277', 'Mountain Bike Tube', 2000), 
    'FR201': Part('FR201', 'Mountain Bike Frame', 60000), 
} 

Product = collections.namedtuple('Product', 'key name parts') 
product = Product(
    'bike201', 
    'Mountain Bike', 
    [('WH239', 2), ('TR202', 2), ('TU277', 2), ('FR201', 1)] 
) 

那麼你可以做是這樣的：

product_price = sum(n*parts[part_name].price for part_name, n in product.parts) 

Answer 2

>>> from collections import Counter 
>>> d1 = dict(a=1, b=2) 
>>> d2 = dict(a=2, b=1, c=3) 
>>> c = Counter(**d1) 
>>> c.update(**d2) 
>>> c 
Counter({'a': 3, 'c': 3, 'b': 3})