设置面积图openpyxl的透明度（alpha）

Question

我想使用 openpyxl 设置面积图背景的透明度。我的图表代码是：

from openpyxl.drawing.fill import PatternFillProperties, ColorChoice

c2 = AreaChart()
c2.grouping = 'stacked'
c2.add_data(data, titles_from_data=True)

c2_s1 = c2.series[0]
fill = PatternFillProperties()
fill.background = ColorChoice(srgbClr="FFFFFF")

c2_s2.graphicalProperties.pattFill = fill

我尝试过使用rgba十六进制编码。

fill.background = ColorChoice(srgbClr="80FFFFFF")

我也尝试过使用

SystemColor

，但我找不到任何如何使用它的示例，并且我所做的每一次尝试都失败了

Answer 1

扩展颜色选择

from openpyxl.compat import unicode
from openpyxl.descriptors import Typed
from openpyxl.descriptors.serialisable import Serialisable
from openpyxl.descriptors.nested import NestedInteger
from openpyxl.xml.constants import DRAWING_NS


class MyRGBColor(Serialisable):
    tagname = 'srgbClr'
    namespace = DRAWING_NS
    val = Typed(expected_type=unicode)
    alpha = NestedInteger(allow_none=True)
    __elements__ = ('alpha', )

    def __init__(self, val, alpha=None):
        self.val = val
        self.alpha = alpha


class MyColorChoice(ColorChoice):
    srgbClr = Typed(expected_type=MyRGBColor, allow_none=True)

..和

c2_s1.graphicalProperties.solidFill = MyColorChoice(
        srgbClr=MyRGBColor('0000FF', alpha=50000))

Answer 2

来自文档：
值的类型必须为

class openpyxl.drawing.effect.AlphaBiLevelEffect

搜索图案填充属性
图案填充属性
如果这对您有用，请返回并将您的问题标记为已回答，或评论为什么不可行。

Answer 3

我怀疑如果不修改 openpyxl 源代码，您想要做的事情目前是不可能的。请参阅“此拉取请求”以获取更多信息。

Answer 4

更新了 @Mosaic 的

openpyxl==3.1.2

实现并进行了一些调整：

from typing import Optional
from openpyxl.descriptors import Typed
from openpyxl.descriptors.serialisable import Serialisable
from openpyxl.descriptors.nested import NestedInteger
from openpyxl.xml.constants import DRAWING_NS
from openpyxl.drawing.colors import ColorChoice


class RGBAColor(Serialisable):
    tagname = 'srgbClr'
    namespace = DRAWING_NS
    val = Typed(expected_type=str)
    alpha = NestedInteger(allow_none=True)
    __elements__ = ('alpha', )

    def __init__(self, hex: str, alpha: Optional[float] = None):
        if alpha != None and not (0 <= alpha <= 1):
            raise ValueError('Alpha value must be between 0 and 1')

        self.val = hex.replace('#', '')
        if alpha: self.alpha = alpha * 10**5

class ExtendedColorChoice(ColorChoice):
    srgbClr = Typed(expected_type=RGBAColor, allow_none=True)

用途：

from openpyxl.chart.series import Series
from openpyxl.chart.shapes import GraphicalProperties


series: Series = chart.series[0]
series.graphicalProperties = GraphicalProperties()
series.graphicalProperties.solidFill = ExtendedColorChoice(
    srgbClr=RGBAColor('#F79D56', alpha=0.5)
)