如何循环定义的元素列表

Question

我有一个很大的列表字典，它是作为更大 python 程序的一部分动态生成的。这是字典的示例

params = {
'output': ['quantity_tot_1m', 'quantity_tot_3m', 'quantity_tot_6m',
'quantity_tot_12m', 'quantity_tot_full', 'cost_tot_1m', 'cost_tot_3m', 'cost_tot_6m', 'cost_tot_12m', 'cost_tot_full', 'selling_tot_1m', 
'selling_tot_3m', 'selling_tot_6m', 'selling_tot_12m', 'selling_tot_full', 'profit_tot_1m', 'profit_tot_3m', 'profit_tot_6m', 'profit_tot_12m', 'profit_tot_full'], 
'agg_types': ['By SKU - 01 Month','By SKU - 03 Months','By SKU - 06 Months','By SKU - 12 Months']
}

我需要帮助才能循环浏览这些列表

我试过下面的

from jinjasql import JinjaSql
j = JinjaSql(param_style='pyformat')

QUERY_TEMPLATE = """
{% set mix_agg = agg_types|replace("[","")|replace("]","") %}
{% set mix_agg2 = cycler(mix_agg) %}
{% for o in output %}
ROUND(CAST(SUM(CASE WHEN agg_type = '{{ mix_agg2.next() | sqlsafe }}' THEN profit_tot ELSE 0 END ) AS NUMERIC),2) AS {{o | sqlsafe}} {% endfor%}
"""

query, bind_params = j.prepare_query(QUERY_TEMPLATE, params)
print(query)

这不会遍历列表，它只是按原样输出列表。当然我不能明确地将列表输入循环仪，因为它必须是动态的。

也许 cycler() 不是最好的方法，但我需要如下所示的输出：

ROUND(CAST(SUM(CASE WHEN agg_type = 'By SKU - 01 Month' THEN profit_tot ELSE 0 END ) AS NUMERIC),2) AS profit_tot_1m,

ROUND(CAST(SUM(CASE WHEN agg_type = 'By SKU - 03 Months' THEN profit_tot ELSE 0 END ) AS NUMERIC),2) AS profit_tot_3m,

ROUND(CAST(SUM(CASE WHEN agg_type = 'By SKU - 06 Months' THEN profit_tot ELSE 0 END ) AS NUMERIC),2) AS profit_tot_6m,

ROUND(CAST(SUM(CASE WHEN agg_type = 'By SKU - 12 Months' THEN profit_tot ELSE 0 END ) AS NUMERIC),2) AS profit_tot_12m

不是这样的：

ROUND(CAST(SUM(CASE WHEN agg_type = 'By SKU - 01 Month', 'By SKU - 03 Months', 'By SKU - 06 Months', 'By SKU - 12 Months' THEN profit_tot ELSE 0 END ) AS NUMERIC),2) AS profit_tot_1m,

ROUND(CAST(SUM(CASE WHEN agg_type = 'By SKU - 01 Month', 'By SKU - 03 Months', 'By SKU - 06 Months', 'By SKU - 12 Months' THEN profit_tot ELSE 0 END ) AS NUMERIC),2) AS profit_tot_3m,

ROUND(CAST(SUM(CASE WHEN agg_type = 'By SKU - 01 Month', 'By SKU - 03 Months', 'By SKU - 06 Months', 'By SKU - 12 Months' THEN profit_tot ELSE 0 END ) AS NUMERIC),2) AS profit_tot_6m,
 
ROUND(CAST(SUM(CASE WHEN agg_type = 'By SKU - 01 Month', 'By SKU - 03 Months', 'By SKU - 06 Months', 'By SKU - 12 Months' THEN profit_tot ELSE 0 END ) AS NUMERIC),2) AS profit_tot_12m

共有20个输出列{{o | sqlsafe}}

Answer 1

行

{% set mix_agg = agg_types|replace("[","")|replace("]","") %}

将数组类型转换为字符串，这只会让以后更难使用，而且可能不是您想要的。

行

{% set mix_agg2 = cycler(mix_agg) %}

然后创建一个循环器，其中有一个字符串可以循环 - 所以它会重复 return 这个字符串。

要循环遍历数组，请使用 python * 运算符 - 它将数组转换为函数参数：

{% set mix_agg2 = cycler(*agg_types) %}

综合起来我们有：

QUERY_TEMPLATE = """
{% set mix_agg2 = cycler(*agg_types) %}
{% for o in output %}
ROUND(CAST(SUM(CASE WHEN agg_type = '{{ mix_agg2.next() | sqlsafe }}' THEN profit_tot ELSE 0 END ) AS NUMERIC),2) AS {{o | sqlsafe}}
{% endfor %}
"""

此外：output 包括 agg_types 中缺少的 _tot_full。您可以通过将其添加到 agg_types 或在定义它们时将其从 output 中删除来解决此问题，或者添加 if 以在循环中跳过它。

如何循环定义的元素列表

How to cycle through a defined list of elements

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