调试Python代码

Question

After a few days I still cannot figure out how to make this work on python (not an experienced programmer). Here it is the code pasted and at the bottom, the expected result:

color_list = ["red", "blue", "orange", "green"]
secuence = ["color", "price"]
car_list = []


def create_list(color_list, secuence, car_list):
    for num in range(len(color_list)):
        car_list.append = dict.fromkeys(secuence)
        car_list[%s]['color'] = color_list[%s] %num    
    return car_list

This is the result I want to achieve:

>> car_list
[{'color': 'red', 'price': None},{'color': 'blue', 'price': None},{'color': 'orange', 'price': None},{'color': 'green', 'price': None}]

Answer 1

You can do it all in one line for this particular scenario, assuming that 'color' and 'price' are constants.

car_list = [{'color': color, 'price': None} for color in color_list]

See list comprehension - it's a powerful tool.

---

If you also had a list of prices, price_list , you could do something similar:

car_list = [{'color': color, 'price': price} for color, price in zip(color_list, price_list)]

See the built in function zip() .

---

If the strings 'color' and 'price' are unknown at the time of execution (which I think is unlikely), you could do something similar to the following

car_list = [{secuence[0]: color, secuence[1]: price} for color, price in zip(color_list, price_list)]

Answer 2

Try the following I'm not sure your can use key addressing not but here I have used it.

def create_list(color_list, secuence, car_list): 
    for each in color_list:
        tmp = dict.fromkeys(secuence)
        tmp['color'] = each
        car_list.append(tmp)
    return car_list