Question

我在列表中有一组元组，我试图将类似的项目组合在一起。例如

[('/Desktop/material_design_segment/arc_01.texture', 'freshnel_intensity_3.0022.jpg'),
 ('/Desktop/material_design_segment/arc_01.texture', 'freshnel_intensity_4.0009.jpg'),
 ('/Desktop/material_design_segment/arc_08.texture', 'freshnel_intensity_8.0020.jpg'),
 ('/Desktop/material_design_segment/arc_05.texture', 'freshnel_intensity_5.0009.jpg'),
 ('/Desktop/material_design_filters/custom/phase_03.texture', 'rounded_viscosity.0002.jpg'),
 ('/Desktop/material_design_filters/custom/phase_03.texture', 'freshnel_intensity_9.0019.jpg')]

我的结果应该归还给我：

'/Desktop/material_design_segment/arc_01.texture':
    'freshnel_intensity_3.0022.jpg',
    'freshnel_intensity_4.0009.jpg',
'/Desktop/material_design_segment/arc_08.texture':
    'freshnel_intensity_8.0020.jpg'
'/Desktop/material_design_segment/arc_05.texture':
    'freshnel_intensity_5.0009.jpg'
'/Desktop/material_design_filters/custom/phase_03.texture':
    'rounded_viscosity.0002.jpg',
    'freshnel_intensity_9.0019.jpg'

但是，当我尝试按如下方式使用我的代码时，它只返回1项。

groups = defaultdict(str)
for date, value in aaa:
    groups[date] = value

pprint(groups)

这是输出：

{'/Desktop/material_design_segment/arc_01.texture': 'freshnel_intensity_4.0009.jpg'
 '/Desktop/material_design_filters/custom/phase_03.texture': 'freshnel_intensity_9.0019.jpg'
 '/Desktop/material_design_segment/arc_08.texture': 'freshnel_intensity_8.0020.jpg'
 '/Desktop/material_design_segment/arc_05.texture': 'freshnel_intensity_5.0009.jpg'}

我在哪里做错了？

Answer 1

您将value分配给groups[date]，这会覆盖之前的值。您需要将其附加到列表中。

groups = defaultdict(list)
for date, value in aaa:
    groups[date].append(value)

Answer 2

您应该按如下方式将值附加到列表中（基于您的代码）：

groups = defaultdict(list)
for date, value in aaa:
    groups[date].append(value)

print(groups)

在列表中对元组进行分组

2 个答案: