如何对 python pandas 或大查询的多列进行数据透视操作。最好是大查询

Question

原始数据：

所需转换后数据的外观：

我在 python pandas 中尝试过 melt 函数，但我只能在一列上旋转。我确定我一定遗漏了一些东西。

Answer 1

以下适用于 BigQuery 标准 SQL

execute immediate (
with types as (
  select 
    array_to_string(types, ',') values_list,
    regexp_replace(array_to_string(types, ','), r'([^,]+)', r'""') columns_list
  from (
    select regexp_extract_all(to_json_string(t), r'"([^""]+)":') types
    from (
      select * except(Country, Branch, Category)
      from `project.dataset.your_table` limit 1
    ) t
  )
), categories as (
  select distinct Category  
  from `project.dataset.your_table`
)
select '''
select Country, Branch, Output, ''' || 
  (select string_agg(''' 
  max(if(Category = "''' || Category || '''", val, null)) as ''' || Category ) 
  from categories)
|| ''' 
from (
  select Country, Branch, Category, 
    type[offset(offset)] Output, val 
  from `project.dataset.your_table` t,
  unnest([''' || values_list || ''']) val with offset,
  unnest([struct([''' || columns_list || '''] as type)])
)
group by Country, Branch, Output
'''
from types
);

如果应用于您问题中的示例数据 - 输出为

如何对 python pandas 或大查询的多列进行数据透视操作。最好是大查询

How to do pivot operation on multiple columns on python pandas or big query. Preferably on big query

python

transpose

pivot

pandas

google-bigquery