python - 列表理解，如果不在第二个列表中则有值(value)

Question

如果周存在于 sales else 0 中，是否可以使用列表理解来获取每周的销售额？

weeks = [{'week': 31}, {'week': 32}, {'week': 33}, 
         {'week': 34}, {'week': 35}, {'week': 36}]
weeks = [x['week'] for x in weeks]

sales = [
    {'week': 32, 'sales': 1167.26}, 
    {'week': 33, 'sales': 1373.61}, 
    {'week': 36, 'sales': 1491.43}, 
]

expected = [0, 1167.26, 1373.61, 0, 0, 1491.43]

Answer 1

您可以根据 sales 创建一个字典，用作查找 weeks 中的每一周:

weeks = [{'week': 31}, {'week': 32}, {'week': 33}, 
     {'week': 34}, {'week': 35}, {'week': 36}]

sales = [
{'week': 32, 'sales': 1167.26}, 
{'week': 33, 'sales': 1373.61}, 
{'week': 36, 'sales': 1491.43}, 
]
_sales = {i['week']:i['sales'] for i in sales}
results = [_sales.get(i['week'], 0) for i in weeks]

输出:

[0, 1167.26, 1373.61, 0, 0, 1491.43]