python - 组合两个 for 循环来填充同一个字典

Question

我试图从字典列表中获取两个不同的商家，优先考虑有价格的商家，如果没有找到两个不同的商家有价格，则商家 1 或 2 的价格将填充列表中的数据，如果列表不够，商家 1 或 2 应为“无”。

即for循环将返回两个商家，优先有价格的商家，如果不足以填充商家(1或2)则获取没有价格的商家。最后如果商家1或2仍未创建则填充它们无值。

这是我到目前为止的代码，它完成了工作，但我相信它可以以更 Pythonic 的方式组合。

import csv
with open('/home/timmy/testing/example/example/test.csv') as csvFile:
    reader=csv.DictReader(csvFile)
    for row in reader:
        dummy_list.append(row)
item=dict()
index = 1
for merchant in dummy_list:
    if merchant['price']:
        if index==2:
            if item['merchant_1']==merchant['name']:
                continue
        item['merchant_%d'%index] = merchant['name']
        item['merchant_%d_price'%index] = merchant['price']
        item['merchant_%d_stock'%index] = merchant['stock']
        item['merchant_%d_link'%index] = merchant['link']
        if index==3:
            break
        index+=1

for merchant in dummy_list:
    if index==3:
        break
    if index<3:
        try:
            if item['merchant_1']==merchant['name']:
                continue
        except KeyError:
            pass
        item['merchant_%d'%index] = merchant['name']
        item['merchant_%d_price'%index] = merchant['price']
        item['merchant_%d_stock'%index] = merchant['stock']
        item['merchant_%d_link'%index] = merchant['link']
        index+=1

while index<3:
    item['merchant_%d'%index] = ''
    item['merchant_%d_price'%index] = ''
    item['merchant_%d_stock'%index] = ''
    item['merchant_%d_link'%index] = ''
    index+=1
print(item)

这是 csv 文件的内容:

price,link,name,stock
,https://www.samsclub.com/sams/donut-shop-100-ct-k-cups/prod19381344.ip,Samsclub,
,https://www.costcobusinessdelivery.com/Green-Mountain-Original-Donut-Shop-Coffee%2C-Medium%2C-Keurig-K-Cup-Pods%2C-100-ct.product.100297848.html,Costcobusinessdelivery,
,https://www.costco.com/The-Original-Donut-Shop%2C-Medium-Roast%2C-K-Cup-Pods%2C-100-count.product.100381350.html,Costco,
57.99,https://www.target.com/p/the-original-donut-shop-regular-medium-roast-coffee-keurig-k-cup-pods-108ct/-/A-13649874,Target,Out of Stock
10.99,https://www.target.com/p/the-original-donut-shop-dark-roast-coffee-keurig-k-cup-pods-18ct/-/A-16185668,Target,In Stock
,https://www.homedepot.com/p/Keurig-Kcup-Pack-The-Original-Donut-Shop-Coffee-108-Count-110030/204077166,Homedepot,Undertermined

Answer 1

由于您只想保留最多 2 个商家，因此我只会处理一次 csv，分别保存有价格的商家列表和没有价格的商家列表，一旦找到 2 个有价格的商家就停止。

在该循环之后，我将连接这 2 个列表和两个空商家的列表，并获取其中的前 2 个元素。这足以保证您对 2 个不同商家的要求，并且优先于那些有价格的商家。最后，我将用它来填充 item 字典。

代码为:

import csv

with open('/home/timmy/testing/example/example/test.csv') as csvFile:
    reader=csv.DictReader(csvFile)

    names_price = set()
    names_no_price = set()
    merchant_price = []
    merchant_no_price = []
    item = {}

    for merchant in reader:
        if merchant['price']:
            if not merchant['name'] in names_price:
                names_price.add(merchant['name'])
                merchant_price.append(merchant)
                if len(merchant_price) == 2:
                    break;
        else:
            if not merchant['name'] in names_no_price:
                names_no_price.add(merchant['name'])
                merchant_no_price.append(merchant)

    void = { k: '' for k in reader.fieldnames}
    merchant_list = (merchant_price + merchant_no_price + [void, void.copy()])[:2]

    for index, merchant in enumerate(merchant_list, 1):
        item['merchant_%d'%index] = merchant['name']
        item['merchant_%d_price'%index] = merchant['price']
        item['merchant_%d_stock'%index] = merchant['stock']
        item['merchant_%d_link'%index] = merchant['link']